GLOBAL_DEBUG is actually not in scope:
```
(venv_c2g)Jasons-MacBook-Pro:main jbau$ ./manage.py issue_certificate_multi -P db--Winter2013 exclusions.txt desc.json 
Traceback (most recent call last):
  File "./manage.py", line 10, in <module>
    execute_from_command_line(sys.argv)
  File "/Users/jbau/projects/venv_c2g/lib/python2.7/site-packages/django/core/management/__init__.py", line 443, in execute_from_command_line
    utility.execute()
  File "/Users/jbau/projects/venv_c2g/lib/python2.7/site-packages/django/core/management/__init__.py", line 382, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/Users/jbau/projects/venv_c2g/lib/python2.7/site-packages/django/core/management/base.py", line 196, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "/Users/jbau/projects/venv_c2g/lib/python2.7/site-packages/django/core/management/base.py", line 232, in execute
    output = self.handle(*args, **options)
  File "/Users/jbau/projects/class2go/main/tools/certificates/management/commands/issue_certificate_multi.py", line 156, in handle
    if GLOBAL_DEBUG: debug_out("Option processing complete, memoizing working objects")
UnboundLocalError: local variable 'GLOBAL_DEBUG' referenced before assignment
```