Create a cgminer specific gettimeofday wrapper that is always called with tz set to NULL and increases the resolution on windows.
Replace gettimeofday usage in cgminer.c with cgtime
Use cgtime instead of gettimeofday in fpgautils.c
Use cgtime in compat.h
Use cgtime in driver-ztex.c
Use cgtime wrapper in driver-modminer.c
Use cgtime in driver-opencl.c
Use cgtime in usbutils.c
Use cgtime in logging.c
Use cgtime in driver-bitforce.c
Use cgtime in driver-icarus.c
Use cgtime in driver-avalon.c
Fix warning on building avalon on win32
Move util.c exports to util.h