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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-Auto indenter in code editor, this makes it much easier to paste external code.
-Zoom in 2D viewport now uses the mouse pointer as reference.
-Obscure hack to see where code/line of GDScript in C++ backtrace.
-Fixed a bug where keys would get stuck on X11 if pressed simultaneously
-Added Api on IP singleton to request local IPs.
-Premultiplied alpha support when importing texture, editing PNGs and as a blend mode.
-Added new screen resizing options, stretch_2d is removed, new much more flexible ones.
-Fixed bug in viewport (can create more instances in 3d-in-2d demo now)
-Can set android permissions and screen sizes manually in the export settings
-Changed export templates extension to .tpz (too many people unzipped the manually..)
-File dialog now ensures that the proper extension is used (will not allow to save without it)
-Fixed bug that made collision exceptions not work in 2D
-Detect when free() might crash the project and throw error
-fixed 2D Bounce in physics (3d still broken)
-renamed “on_top” property to “behind_parent”, which makes more sense, old on_top remains there for compatibility but is invisible.
-large amount of fixes
