Added DCO policy and clarified License

Parts of this are inspired by https://raw.githubusercontent.com/chef/chef/master/CONTRIBUTING.md

Signed-off-by: Harshad RJ <harshad.rj@gmail.com>

CONTRIBUTING.md

@@ -1,14 +1,10 @@
 # Contributing to gngr
 
-### Avoid +1s on issues
-Please avoid spamming issues with `+1`s. Unfortunately, Github doesn't have a way to vote on an issue. Shoot a mail to
-[them](mailto:support@github.com) if you agree that ability to vote on an issue is essential.
+We are glad you want to contribute to `gngr`! This document will help answer common questions you may have during your first contribution.
 
 ### Testing and reporting issues
 This is the simplest way of contributing to `gngr`: use it and when you find bugs shoot us an issue report on GitHub.
 
-We also need help in running systematic tests (such as tests from W3C). We will write more about that later.
-
 ### Triaging
 When an issue is reported by a user, we need help in diagnosing the root cause and breaking it down to a small
 test-case. This often requires familiarity with the browser stack (HTTP, HTML, CSS, JS, etc), while knowledge of
@@ -21,7 +17,15 @@ We often need advice / guidance from experts in browser and related technologies
 Please [search for issues with the `need-advice` label](https://github.com/UprootLabs/gngr/labels/need-advice).
 
 ### Code
-Everyone is welcome to contribute. Issues that can be easily picked up are marked with the
+
+We have a 3 step process for contributions:
+
+* Commit changes to a git branch, making sure to sign-off those changes for the [Developer Certificate of Origin](#developer-certification-of-origin-dco).
+* Create a Github Pull Request for your change, following the instructions in the pull request template.
+* Perform a Code Review with the project maintainers on the pull request.
+
+
+Issues that can be easily picked up are marked with the
 following tags:
 * [need-code](https://github.com/UprootLabs/gngr/labels/need-code) : if you are ready to jump in with code.
 * [need-advice](https://github.com/UprootLabs/gngr/labels/need-advice) : if you have expertise on the topic.
@@ -31,3 +35,85 @@ Ofcourse, you are welcome to take up something that is not listed above, but ple
 before you spend effort on it.
 
 You can also contribute to our [upstream projects](https://gngr.info/doc/credits.html).
+
+### Developer Certification of Origin (DCO)
+### Developer Certification of Origin (DCO)
+Licensing is very important to open source projects. It helps ensure the software continues to be available under the terms that the author desired.
+
+Gngr uses GPL and LGPL licenses to strike a balance between open contribution and allowing you to use the software however you would like to.
+
+The license tells you what rights you have that are provided by the copyright holder. It is important that the contributor fully understands what rights they are licensing and agrees to them. Sometimes the copyright holder isn't the contributor, such as when the contributor is doing work on behalf of a company.
+
+To make a good faith effort to ensure these criteria are met, `gngr` requires the Developer Certificate of Origin (DCO) process to be followed.
+
+The DCO is an attestation attached to every contribution made by every developer. In the commit message of the contribution, the developer simply adds a Signed-off-by statement and thereby agrees to the DCO, which you can find below or at <http://developercertificate.org/>.
+
+```
+Developer's Certificate of Origin 1.1
+
+By making a contribution to this project, I certify that:
+
+(a) The contribution was created in whole or in part by me and I
+    have the right to submit it under the open source license
+    indicated in the file; or
+
+(b) The contribution is based upon previous work that, to the
+    best of my knowledge, is covered under an appropriate open
+    source license and I have the right under that license to   
+    submit that work with modifications, whether created in whole
+    or in part by me, under the same open source license (unless
+    I am permitted to submit under a different license), as
+    Indicated in the file; or
+
+(c) The contribution was provided directly to me by some other
+    person who certified (a), (b) or (c) and I have not modified
+    it.
+
+(d) I understand and agree that this project and the contribution
+    are public and that a record of the contribution (including
+    all personal information I submit with it, including my
+    sign-off) is maintained indefinitely and may be redistributed
+    consistent with this project or the open source license(s)
+    involved.
+```
+
+For more information on the change see the Gngr Blog post (TODO)
+
+#### DCO Sign-Off Methods
+
+The DCO requires a sign-off message in the following format appear on each commit in the pull request:
+
+```
+Signed-off-by: XXXX <XXXX@xyz.com>
+```
+
+The DCO text can either be manually added to your commit body, or you can add either **-s** or **--signoff** to your usual git commit commands. If you forget to add the sign-off you can also amend a previous commit with the sign-off by running **git commit --amend -s**. If you've pushed your changes to Github already you'll need to force push your branch after this with **git push -f**.
+
+### Gngr Obvious Fix Policy
+
+Small contributions, such as fixing spelling errors, where the content is small enough to not be considered intellectual property, can be submitted without signing the contribution for the DCO.
+
+As a rule of thumb, changes are obvious fixes if they do not introduce any new functionality or creative thinking. Assuming the change does not affect functionality, some common obvious fix examples include the following:
+
+- Spelling / grammar fixes
+- Typo correction, white space and formatting changes
+- Comment clean up
+- Bug fixes that change default return values or error codes stored in constants
+- Adding logging messages or debugging output
+- Changes to 'metadata' files like Gemfile, .gitignore, build scripts, etc.
+- Moving source files from one directory or package to another
+
+**Whenever you invoke the "obvious fix" rule, please say so in your commit message:**
+
+```
+------------------------------------------------------------------------
+commit xxxxxxx
+Author: yyyyyyyyyy
+Date:   Wed Sep 18 11:44:40 2015 -0700
+
+  Fix typo in the README.
+
+  Obvious fix.
+
+------------------------------------------------------------------------
+```

README.md

@@ -66,7 +66,9 @@ See [the contributing guide](CONTRIBUTING.md) for more details.
 [GPLv2](https://www.gnu.org/licenses/gpl-2.0.html)
 
  * Copyright 2009 Lobo Project
- * Copyright 2014, 2015 Uproot Labs India Pvt Ltd
+ * Copyright 2014-2018 Uproot Labs India Pvt Ltd
+
+Some parts of the code are provided under the LGPL license. Their directories contain their respective license files.
 
 ### Pre-History
 `gngr` began as a fork of the now-defunct project called the `lobo` browser (see [credits](https://gngr.info/doc/credits.html)).