Revisit includes and excludes logic

[tisonkun]

Currently, we build includes and excludes in Selection using buildOverrideInclusions, buildExclusions and buildInclusions.

I don't think it's a clean way and I don't agree that we should explicitly specify exact includes to remove default exclusions.

Basically, we should evaluate includes and excludes with priority and acting like a painter:

1. Filter if in default includes if no user-defned includes.
2. If in default excludes, pending to be ignored.
3. If in user-defined includes, bring it back.
4. If in user-defined excludes, kick it off again.

In this way, we can append and plugin includes and excludes like the idea in #20 to respect .gitignore configs.

[tisonkun]

Here I meet a case in that we have default excludes **/.svn and user include *.txt, it's hard to determine whether we should skip the folder.

If we evaluate always on files, not only the time consumption will increase, but also ignore a dir should be always folder/**.

[tisonkun]

Refer to mathieucarbou/license-maven-plugin@413e36c#r95274254

[tisonkun]

Fix build inclusion at d8e8ca4.

Maybe we can close this issue as is now.

[tisonkun]

Follow-up by 8cda4b2 to avoid using inclusion for inverting exclusion, but introduce an explicit invert exclusion syntax !<invert-exclude-rule>.

Closing...

Maybe we can learn more from other libraries like gitignore to see how to make better configuration on these things.