svn cleanup: remove automatic call on update, merge, commit, etc.

[benfitzpatrick]

In an old (non-GitHub issue), we noted a problem with Subversion 1.6 and fcm:

fcm merge can result in spurious end of file text in a merged file which appears to arise from the last bytes of an old version of the file.
...
Running svn cleanup immediately before a merge appears to stop the bug. 

We incorporated svn cleanup calls into switch, update, and commit (others?).
This is probably unnecessary at svn 1.7+ with the new working copy format, and can
cause a slowdown for large working copies. We should remove the svn cleanup calls.