Add method to retrieve unique key from Solr connector.
Enable sitemapping of multiple cores/indices.
Resolves VUFIND-656.
Lightbox global update.
VUFIND-871 ticket fix.
Merge branch 'master' of https://github.com/vufind-org/vufind

Conflicts:
	themes/bootstrap/js/lightbox.js
Removed redundant field.
Fixed some spacing in advanced search.
Use solr.TrieDateField instead of solr.DateField
Resolves VUFIND-546.
Merge branch 'master' of https://github.com/vufind-org/vufind
VUFIND-896. SideFacets wrapping as suggested by Ben Mosior.
VUFIND-896. Method 2.