Check if enough args exist in command. Fixes TICKET-29

Check if the command has more that 0 argument before continuing to proccess
command. This fixes the error raised in TICKET-29.
Add more detailed error message when failing to convert areas

Add a more detailed error message stating the area name of the failed conversion to
make it easier to identify future errors.
Make flag command only change one area. Fixes TICKET-27.

Make the flag command only change the flags on the overlapping region. This fixes
TICKET-27.