Add ability to change resolution
Duh - forgot the self...
Commented out ISO

It doesn't do anything at the moment. In fact it seems like ISO needs to
be 0 in order for exposure mode to do anything, but I need to confirm
that...
Various fixes

Use ISO 0 and hide ISO options to enable exposure mode to work, and hide
the verylong exposure mode which is know to crash the camera's firmware
when exposure time reaches a second