Make Search query ignore current category

Search should be run against all possible categories, otherwise it is
much less useful. So, after user submits Search request,
current_category will be set to 'All'. Also page navigation for
multi-paged search results is fixed (it didn't work earlier).

Change-Id: I556fa7cc23f4c004047c36d8aa11097a21a2d477
Closes-Bug: #1307931
Merge "Make Search query ignore current category"