What version are you running?
0.7.5
What steps will reproduce the problem?

Have a registry key with forein character in it in the MIME types database (example: Vidéo pour Adobe Flash)
Use rbt post to upload a review with Perforce (occurs with or without the --update option)
Wait for the diff generation, the error should appear after.


What is the expected output? What do you see instead?
expected output: 

The review diff is generated correclty
what is seen: 

CRITICAL: 'ascii' codec can't decode byte 0xe9 in position 3: ordinal not in range(128) and the review submission fails
What operating system are you using?
Windows 7
Attach the debug out from the command.

$ rbt <command> --debug <args>
<debug output>


Traceback (most recent call last):

  File "C:\Program Files (x86)\RBTools\bin..\Python27\Scripts\rbt-script.py", line 8, in <module>

    load_entry_point('RBTools==0.7.5alpha0', 'console_scripts', 'rbt')()

  File "C:\Program Files (x86)\RBTools\Python27\lib\site-packages\rbtools-0.7.5alpha0-py2.7.egg\rbtools\commands\main.py

", line 133, in main

    command.run_from_argv([RB_MAIN, command_name] + args)

  File "C:\Program Files (x86)\RBTools\Python27\lib\site-packages\rbtools-0.7.5alpha0-py2.7.egg\rbtools\commands_init

_.py", line 622, in run_from_argv

    exit_code = self.main(*args) or 0

  File "C:\Program Files (x86)\RBTools\Python27\lib\site-packages\rbtools-0.7.5alpha0-py2.7.egg\rbtools\commands\post.py

", line 746, in main

validate_kwargs)

  File "C:\Program Files (x86)\RBTools\Python27\lib\site-packages\rbtools-0.7.5alpha0-py2.7.egg\rbtools\api\decorators.p

y", line 27, in request_method

    *args, kwargs)

  File "C:\Program Files (x86)\RBTools\Python27\lib\site-packages\rbtools-0.7.5alpha0-py2.7.egg\rbtools\api\transport\sy

nc.py", line 75, in execute_request_method

    return self._execute_request(request)

  File "C:\Program Files (x86)\RBTools\Python27\lib\site-packages\rbtools-0.7.5alpha0-py2.7.egg\rbtools\api\transport\sy

nc.py", line 84, in _execute_request

    rsp = self.server.make_request(request)

  File "C:\Program Files (x86)\RBTools\Python27\lib\site-packages\rbtools-0.7.5alpha0-py2.7.egg\rbtools\api\request.py",

 line 572, in make_request

    content_type, body = request.encode_multipart_formdata()

  File "C:\Program Files (x86)\RBTools\Python27\lib\site-packages\rbtools-0.7.5alpha0-py2.7.egg\rbtools\api\request.py",

 line 119, in encode_multipart_formdata

    mime_type = mimetypes.guess_type(filename)[0]

  File "C:\Program Files (x86)\RBTools\Python27\lib\mimetypes.py", line 297, in guess_type

    init()

  File "C:\Program Files (x86)\RBTools\Python27\lib\mimetypes.py", line 358, in init

    db.read_windows_registry()

  File "C:\Program Files (x86)\RBTools\Python27\lib\mimetypes.py", line 258, in read_windows_registry

    for subkeyname in enum_types(hkcr):

  File "C:\Program Files (x86)\RBTools\Python27\lib\mimetypes.py", line 249, in enum_types

    ctype = ctype.encode(default_encoding) # omit in 3.x!

UnicodeDecodeError: 'ascii' codec can't decode byte 0xe9 in position 3: ordinal not in range(128)
Please provide any additional information below.
This started to happen after installing Adobe Flash (french version). Changing the 'é' character in the registry key for an 'e' bypassed the issue.