fixing watchdog messages from packaging script

the current watchdog behavior in the packaging script is driving me nuts. ;) it was helpful during initial development, but now it's way too much noise, and too hard to figure out when there really are problems. attached patch does the following:

• all regular messages are now split to either 'package_branch' or 'package_tag' to keep those runs separate
• only print "Starting to package..." for branches, not the every-5-minutes tag runs
• only print "Done packaging..." if we packaged anything or if it's a branch run (since those are only 2/day, and it'd be helpful to see if we did runs and didn't package anything).
• all errors (from either branch or tag) continue to go to 'package_error'
• to make it easier to change later (if we ever want to) all watchdog levels are specified by a few global vars.