adds TabsEditingDescriptor, pluggen in VideoAlphaDescriptor
styling for the second level of tabs in the video alpha module editor
Changes CodeMirror mode from HTML to XMl
renames codemirror-edit.html to videoalpha/codemirror-edit.html
renames advanced-editor -> xml_editor
removes obsolete comment
renames cms/templates/widgets/tabs/metadata-edit-tab.html to video-..
removes lates specific code
fixes for: removes latex code
moving the video alpha second level tab styling to its own stylesheet
removes coupling of save method in tab templates
removes dublicated comment
removes hardcoded settings tab