First attempt on splitting Custom Build System into 2 parts.
Fix issue when converted settings were not written.
Also add all parent's includes/defines.
Add more test cases.
Don't replicate defines.
Beautify code slightly.
Add thread synchronization just in case.
Add IDefinesAndIncludesManager interface.
Port CustomDefinesAndIncludesManager to the interface.
Futher code clean up.
Move IncludesAndDefines plugin into language folder.
Add tests for the plugin.
Bring back some debug. Add missing files.
Remove some unused code/files. Fix copyright issues.
Test clean up.
Add support for auto includes.
Clean up headers.
Clean up the code.
Fix indentation.
Generate test projects automatically at runtime.