Display plugin description when it is selected

When you select an element or visualization or a form, list or
validation plugin, if the description is available in the *.sys.ini
files it will display it as help for the user.
Tweak HTML to leave space after delete button.
Make element display consistent
Remove unneeded add button in repeating subopt
Add back in missing element files
Remove deprecated Kaltura element
Remove suprious duplicated file
Remove deprecated Sugarid element
Remove spurious mytristate files
Remove incorrect viewlevel strings

These have user strings in them.
Remove deprecated video plugin
Add missing index.html files
Make element display in back-end consistent

Ensure that description is displayed, put help button on every tab of
multi-tab options etc.