TRIBS-134 IAC FTSearch on all fields combined into one

TRIBS-134 IAC FTSearch Fix null concatenation. Add test for metadata search.

TRIBS-134 IAC FTSearch Modify index to use coalesce. Fix for TRIBS-167.

TRIBS-134 AAC Full text search metadata fields.

TRIBS-134 AAC Add file number parts to full text search. Add rake task for assigning missing file numbers.

Remove redundant line in test.
Merge pull request #85 from ministryofjustice/aac-search

TRIBS-134 AAC Add file number parts to full text search