libsbig: change default ABG from CLK_MED to OFF
libsbig: add some inline comments to camera.c
libsbig: add flags to start/end_exposure()
sbig-snap: call start/end_exposure with flags

The only actual flag we are passing that is new, is when
we start, we call end_exposure to abort any in-progress exposure
with the ABORT_DONT_END flag.
sbig-snap: sleep during integration
sbig-snap: add -r, --resolution lo,med,hi option
sbig-util: add temp control functions
libsbig: remove redundant temp status call
sbig-info: add 'cooler' target
sbig-cooler: added new temp control util