Update the event module

Update the event module to match ding2 DDB base theme design and better match ding2 core coding guidelines.

 * Fields have been rename to match guidelines.
 * Views and panels update with fieldnames.
 * Added support for place2book extension.
 * Re-export in relation to new feature version.
 * A lot of clean up to match ding2 DDB base theme and wishes from ding team.

Work by:

 * wiredloose <ea@vejlebib.dk>
 * Brian Jensen <mail@magnify.dk>
 * Arni <al@randersbib.dk>
 * Rasmus Frey <rasmus@artz.dk>
 * Agnete Moos <agms@sonderborg.dk>