Load GeoNode CSS assets after vendor CSS when DEBUG_STATIC is true.
Move activity.less to base.less and add activity styling.  Fixes #1572.
Date picker improvements.

* Add the date picker css to minified assets.
* Set the date picker to auto close on select.
* Date picker input forms use entire column.
Minor style fixes.

* Add padding to the top of the wrap divs.
* Use the pointer cursor over nav pills.
Add ZeroClipboard.min.js and moment.min.js to the gitignore.