Added without_assisgned_location field to dc-search form.
Enables to search dc-assets without location fields.
Location fields are: data_center, server_room, rack, etc.
Merge pull request #520 from xliiv/no-location-in-search-ok

Added without_assisgned_location field to dc-search form.
Merge remote-tracking branch 'allegro/develop' into location