Tightened up CSS selectors

The CSS selectors used to define the different blocks on many NIPAP
pages (classes option-groups and options) were very general and set
properties to every child element of the option divs. This for example
made the new, Angularified, VRF-selector menu look.. ugly.

To address this the CSS selectors were tightened up to only apply to
elements at specific places in the tree. I might have overlooked some of
the consequences of this...
Upgraded Angular UI Bootstrap to 0.11.0

Upgraded Angular UI Bootstrap to 0.11.0 to get the onToggle-directive
for dropdowns.
Fixes to the VRF selector on the add prefix page

Some fixes to the VRF selector on the add prefix page.
* Perform search with empty search string initially, to populate with
  the default VRF.
* Focus the text box when the VRF selector is opened.
Fixed tag input with Angularified tag-widget

Fixed tag input on add preefix page with an angularified tag-widget. So
far it does not look anything like the old one, but that can be changed.