Various improvements.

Various improvements.

* Remove legacy SVN gunk
* Add consistency to paths
* Make rss-from-git, rss-from-svn and rss-from-vc consistent: last is
  the preferred method
* Create XHTMLCOMPILER constant in view of future "put your
  xhtml-compiler" directory anywhere functionality
* Delay error reporting so parse errors get spit out
* Improve htaccess.php code; shorten $new_contents and error msg.

Signed-off-by: Edward Z. Yang <edwardzyang@thewritingpot.com>