-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
target-fps working, and use fixed physics step before adding physics-fps in project setting
Complete implementation of framelimit
Conflicts:
main/main.cpp
In `class OS_Unix` the arguments in the `execute` method are converted
to UTF-8, but in the `main` program's method they're inserted into a
wide-char `Vector` before translating them from UTF-8 and thus the
non-ASCII characters are lost.
This fix converts the `argv` elements to UTF-8 using `String::utf8`
before inserting them in the `Vector`.
-load() was in the GDScript docs but missing in the scripting-different music for platformer 2D and 3D
-fix how documentation is generated, built in doc browser should be always up to date
-copypaste, scrolling, etc in builtin doc
-built-in scripts get saved now (though debugger may not always work on them)
-Theme can be set to controls as a property
