Update gitignore structure.

Refactor out gitignore in /other/serialTest.
Add some more noticable headers.
Some simplifaction and restructuring.
Clean up some files.
Refactor out lib platform gitignore files.
Refactor out some gitignore files from AdvancedImageLoading.
Remove erroneously committed XCode project components. Closes #2057.
gitignore: correct comment spacing, minor updates.
ofBaseApp: remove mouseReleased(void) - the variant with x/y/button params is always called anyway, so this one was essentially unused and confusing.

fixes #2668
ofMath: remove ofAngleSumRadians. Closes #2747
Merge branch 'master' of github.com:openframeworks/openFrameworks
Merge pull request #2746 from liamstask/ofBaseApp-remove-mouseReleased-void

ofBaseApp: remove mouseReleased(void) - the variant with x/y/button para...
Fixed loadDialogBrowseCallback to return UNICODE string.
In ofSystemLoadDialog, passed windowTitle into dialog box.
Changes to ofGstVideo files to compile with 0.10 gstreamer and fixup file names in Win32.
Merge pull request #2751 from ngbrown/fixGStreamerForWin

Changes to ofGstVideo files to compile with 0.10 gstreamer and fixup file names in Win32
Merge pull request #1 from openframeworks/master

merge openFrameworks master
Fix typo
Clarified some error messages
Clarified some error messages
Added error message when JNIEnv can't be obtained
Fixed error with texture binding in the AndroidVideoGrabber when apps goes to background.
assimp-update
remove unused portaudio sound stream impl.