Improve dashboard implementation.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1169 3c3d7b80-5828-415e-9f61-280b98178fff
Improve dashboard widget implementation. The widget position is still not set correct every time.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1170 3c3d7b80-5828-415e-9f61-280b98178fff