Svn2bzr aborts on UTF8 characters in filenames

[PeterPall]

How to reproduce:
- Commit a file named äöüß.tex or similar to a svn repo
- dump the repo
- run svn2bzr on the dump.

Resultof the command svn2bzr.py dump bazaar
Revision 0 read
Revision 1 read
error: Encountered error: 'ascii' codec can't decode byte 0xc3 in position 1: ordinal not in range(128)
while processing dump entry:
<DumpEntry "{'node-action': 'add', 'node-kind': 'dir', 'prop-content-length': 10, 'node-path': '\\xc3\\xb6', 'content-length': 10}">
Nothing changed in revision 1
...but committing revision properties (revno, message, committer, and timestamp) anyways
Committed revision 1

Will add a minimal svn dump (named "dump") to this bug report that can be used for debugging purposes.