added mask
fixed some errors
rt_pixel added mask parameter and error checks to rt_pixel_set_to_array
minor changes
changed mapalgrebra to except a mask parameter
fixed mapalgerbra raster iterator to accept mask parameter
periodic save
peroidic save
perodic save
perodic save-- fixed logic error
peroidic save
perodic save
peroidic save -- comment
peroidic save
peroidic save-- compiles
peroidic save
fixed segv
added mask parameter to nmapalgerbra
sp error
fixed varadict arg placement