Added the new upload directories and ignore the cache directory completely.

With SugarCRM 6.4 the cache/upload directory moved to upload and
upload_backup. These directories can safely be ignored.

Additionally the cache directory is now ignored completely because it
leads to the behaviour to use the git repository as a kind of backup
tool if several parts of it are included. Furthermore the directory
structure beneath cache is victim of enduring changes by the
developers.

I did also some code cleanup regarding the path names e.g. adding a /
before most file and directory names.