Multivalue fields

Add support for multiplevalue fields for DC and QDC.

Please note that:
* This patch requires https://github.com/mediamosa/mediamosa-ck/pull/24 to work
* The form submit will now save values from $form_state['values'] instead of $form_state['input'] (in order to fix the date_popups not being saved.
* CSS needs to be updated for a cleaner look, but I'm no expert in that :)