Display the extended description for updates and plugins.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1466 3c3d7b80-5828-415e-9f61-280b98178fff
Allow setting multiple lines in the 'Extra options' field.

git-svn-id: http://svn.code.sf.net/p/openmediavault/code/trunk@1467 3c3d7b80-5828-415e-9f61-280b98178fff