#21 With svn and -c switch old revisions are not shown

[Gur Stavi]

Working with diffuse version 0.4.6 and svn version 1.6.18.
When running 'diffuse -c REVISION FILE' diffuse often fails with:
Error reading revision REVISION of FILE.
Generally it succeeds for newer revisions and fails for old ones.
I debugged a little and found that to retrieve the file diffuse uses:
svn cat FILE@REVISION
For some reason this command often fails on my system for older revisions.
The following alternative seems to always work:
svn cat -r REVISION FILE