gles: plumb view matrices to all drawers
gles: plumb through a model matrix
gles: add a shader program helper class
screen: expose brightness
letter: port to opengles-compatible calls
screen: port to opengles-compatible calls
actor: add a close method to actors
starparticle: port to opengles-compatible calls
connectedparticle: port to opengles-compatible calls
WIP: field: port to opengles-compatible calls