OptBox: stopEvent and preventDefault to prevent reload page because of click

It's not neccessary to reload the page to disable/enable cookies
OptBox: only show box if defaultOptValue is out
OptBox: Use jQuery instead of ext.

Simplifies code, step forward to remove ext from frontend.
OptBox: Add feature to define if box should be shown independent of defaultOptValue

This is needed because in some countries optBox needs to be shown even
if the defaultOptValue is 'in' to notify users there are cookies saved
by default.