Don't clean plugins/ folder or config files

Also, if any non-shipped .htaccess files exist, don't clean those either

Fixes #60
Remove placeholder text if found in the draft save

The issue has been filed with Imperavi, but no ticket number or other
tracking information was returned.
Merge pull request #63 from greezybacon/issue/redactor-placeholder-in-draft

Remove placeholder text if found in the draft save

Reviewed-By: Peter Rotich <peter@osticket.com>