running aegean without --mask will no longer cause a crash when you don't have healpy installed
--mask requires healpy and will complain if it can't import AegeanTools/Regions.py
wrote add_poly
updated conversion functions to use lists
refactored code
separated command line arguments into groups for clarity
not supplying any options prints help
enabled +/-p for polygons
renamed cmd line option 'mask' to 'region' as the region file doesn't represent the mask, but the not masked area of sky