Added support for 2D shadow casters.
*DANGER* Shaders in CanvasItem CHANGED, if you are using shader in a
CanvasItem and pull this, you will lose them. Shaders now work through a
2D material system similar to 3D. If you don't want to lose the 2D
shader code, save the shader as a .shd, then create a material in
CanvasItem and re-assign the shader.
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-Moved drawing code to a single function that takes linked list (should make it easier to optimize in the future).
-Implemented Z ordering of 2D nodes. Node2D and those that inherit have a visibility/Z property that affects drawing order (besides the tree order)
-Removed OpenGL ES 1.x support. Good riddance!
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-NOTIFICATION_WM_QUIT fixed on android (seems tha way this is reported changed in newer sdk)
-WIP implementation of APK Expansion APIs for publishing games larger than 50mb in Play Store
-Feaures in the new tutorials are all present in the sourcecode
-This (hopefully) should get rid of the animation list order getting corrupted
-Improved 3D Scene Importer (Skeletons, Animations and other stuff were not being merged). Anything missing?
-In code editor, the automatic syntax checker will only use file_exists() to check preload() else it might freeze the editor too much while typing if the preload is a big resource
-Fixed bugs in PolygonPathFinder, stil pending to do a node and a demo
-IMA-ADPCM support for samples, this means that sound effects can be compressed and use 4 timess less RAM.
-New 3D import workflow based on Wavefront OBJ. Import single objects as mesh resources instead of full scenes. Many people prefers to work this way. Just like the rest of the imported resources, these are updated in realtime if modified externally.
-Mesh resources now support naming surfaces. This helps reimporting to identify which user-created materials must be kept.
-Several fixes and improvements to SurfaceTool.
-Anti Aliasing added to WorldEnvironment effects (using FXAA)
-2D Physics bodies (RigidBody, KinematicBody, etc), Raycasts, Tilemap, etc support collision layers. This makes easy to group which objects collide against which.
-2D Trigger shapes can now also trigger collision reporting in other 2D bodies (it used to be in Area2D before)
-Viewport render target textures can now be filtered.
-Few fixes in GDscript make it easier to work with static functions and class members.
-Several and many bugfixes.
-fix some menus
-fixed bug in out transition curves
-detect and remove file:/// in collada
-remove multiscript for now
-remove dependencies on mouse in OS, moved to Input
-avoid fscache from screwing up (fix might make it slower, but it works)
-funcref was missing, it's there now
