Make scan_itunes take unicode institutions

[sjlegg]

(Mercury)mini-beta:opms steven$ ./manage.py scan_itunes u"東京有明医療大学"
Scan iTunes started at 2012-07-30 14:00:42.967524

Writing errors to: scan_itunes.log
Traceback (most recent call last):
File "./manage.py", line 11, in
execute_manager(settings)
File "/Users/steven/Sites/env/Mercury/lib/python2.7/site-packages/django/core/management/init.py", line 459, in execute_manager
utility.execute()
File "/Users/steven/Sites/env/Mercury/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/steven/Sites/env/Mercury/lib/python2.7/site-packages/django/core/management/base.py", line 196, in run_from_argv
self.execute(_args, *_options.dict)
File "/Users/steven/Sites/env/Mercury/lib/python2.7/site-packages/django/core/management/base.py", line 232, in execute
output = self.handle(_args, *_options)
File "/Users/steven/Sites/env/Mercury/OPMS/opms/monitors/management/commands/scan_itunes.py", line 70, in handle
self._errorlog(institution + u" is not a recognised institution.")
UnicodeDecodeError: 'ascii' codec can't decode byte 0xe6 in position 1: ordinal not in range(128)