Fixing redundant select picker refresh

This issue relates to pull request: https://github.com/mgcrea/angular-strap/pull/246.  

In the select directive, the watch on selected items (ngModel) is firing a select picker refresh when the selected item(s) has changed from a UI event.  The selected item has already been decorated and the UI does not need to be refreshed.

The watch has been changed to check if the document active element is a child of the select picker and skips the select picker refresh accordingly.

I also wrapped the element.selectpicker('refresh') in the refresh function in a $timeout function as it wasn't picking up changes made to the options (tested with 50+ options).

The select tests are now failing and I'm not sure how to fix that.