-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
-made GUI Theme editor usable
-editor does not allow to export or create .pck in the same path as a project
-changed .pck format (lacked support for versioning so couldn't change it), previous was causing crashes and is now incompatible, just re-export.
-will not look for .pck files recursively, was causing unexpected behaviors
-fixed execution of Godot in paths with non unicode characters in Windows, OSX and Linux.
