Write RRD files every 15 minutes (the same interval the graphs are created).

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1288 3c3d7b80-5828-415e-9f61-280b98178fff
Add new option to omv-firstaid to submit the system diagnostic information to the administrator email account.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1289 3c3d7b80-5828-415e-9f61-280b98178fff