Bugfix for edit not working on solutions + bugfixes for problems noticed...

1) Fixes problem with editing for both Calendar & Documents, [SOL-124]

2) Fixes stuff reported by Xavier
In both css files, I think it would be best to include a leading ``.google-calendar-xblock-wrapper`` in the selector - this safely prevents problems in case the class names are used elsewhere. These are good improvements, but do not quite address this specific feedback.