Log Message:
Update to 0.5.2.

Changes:
* Performance improvements.
* Better unicode support in commit-messages.
* TRAC_ADMIN is now a real "meta-permission" containing all other \ 
permissions.
* Wiki-links of the /path format can now also link to directories.
* Handle subversion changesets without any "author" specified.
* "view" checkboxes in the timeline view now reflect the current state.
* The subversion repository is now indexed by "trac-admin initdb"
  instead of trac.cgi at first execution.
* Most of the inline css is removed.
* IE6 navbar problem fixed.
* Various bug fixes.