Mantis 0001021: Add feature to revert configuration changes.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@997 3c3d7b80-5828-415e-9f61-280b98178fff
Improve code.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@998 3c3d7b80-5828-415e-9f61-280b98178fff
* Update locales.
* Unlink configuration backup file.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@999 3c3d7b80-5828-415e-9f61-280b98178fff