Make file targets for code check

[phil-davis]

https://github.com/owncloud/customgroups/blob/master/rules/tests.mk has make targets called:

make test-codecheck
make test-codecheck-deprecations

Other repos seem to have:

make test-php-codecheck

It also has various stuff like:

make test-syntax-php
make test-syntax-js
make test-codecheck-deprecations
...

And it has the whole structure of a rules folder containing various *.mk files.

What is good about the way the build and CI is organized? (and should be replicated consistently to other repos)

What should be refactored in this repo to make it like other app repos?

@PVince81 @DeepDiver1975 @pmaier1

Part of owncloud/QA#582

[phil-davis]

@patrickjahns I just realized that I picked the wrong Patrick when I pinged people for this issue.
Do you know anything about the history of the Makefile structure in this repo?
Or comments about what we should do to "standardize" this?

[phil-davis]

PR #205 sorts out "standardizing" this to be reasonably similar to the way things are organized in the other apps, and removes "excess" stuff from the make files.

That should be enough for now. And we will be refactoring "the makefile universe" again for owncloud/QA#604 when we agree on a design for that.