Distorted Android

New shape: Kilominx corner.

Rex Cube - new mesh, textures and icon.

Fixes for the Rex Cube (mostly works now)

Fixes for the Rex Cube (still doesn't work)

Improve the Ivy mesh.

More support for using the library from more than one activity

1) Beginnings of support for using the library from more than one activity
2) rename DistortedLibrary.onCreate() to onSurfaceCreated()
3) (rubik) add Cambodia's flag.

Minor.

Progress with the Ivy.

Minor.