added const to premultiplied()
log z depth with layer description
added new layer for testing
added hasTexture(), added method for adding a programmatically created texture
added preliminary draw code for round rect, needs at least orientation fix, among others
disabled verious bind() and enable() calls during a bug hunt, don't seem to be necessary
had to disable texture bind state cache since it broke drawing due to textures bein also bound outside of context
added round rect draw code to all layers for initial testing