fts: Added fts_no_autofuzzy setting to require exact matches for found results. This is done by using the FTS search results as only filters on which the regular non-FTS search is done.

fts: Added message_part to fts_backend_build_key. This allows FTS backends to index MIME parts separately from each others.

fts: Added lookup_done() API call. Lucene uses it to close the index. This way it Lucene doesn't keep the index files unnecessarily open forever.

fts: Added fts_backend_rescan()

fts: Redesigned/enhanced FTS API and how virtual plugin works with it. The changes include: - Only indexer process and "doveadm index" do FTS indexing now. Other processes connect to the indexer process via UNIX socket and request indexing a specific mailbox. - FTS backends can now index/search any search key. Current backends implement indexing for some specific header fields (Subject, From, To, Cc, Bcc), but it would also be possible to add indexing for e.g. message size or date. - CLucene support is fixed and fully functional. - Solr is split to "solr" and "solr_old" backends. The new "solr" backend supports the new header fields. It also uses mailbox GUIDs as mailbox identifiers, so that renaming a mailbox doesn't require reindexing. The "solr_old" uses the old Solr schema and doesn't support any new features.

fts: Replaced unnecessary lock()/unlock() from API with refresh()

fts: Backends can now index non-text body parts if they support it. --HG-- branch : HEAD

Finished making full text search indexes work fast with virtual mailboxes. --HG-- branch : HEAD

Added support for sorting by X-SCORE. Currently it's only set by fts-solr. --HG-- branch : HEAD

fts: Added a new lookup API where the backend can look up all the fields using a single query. Implemented it to fts-solr. --HG-- branch : HEAD

FTS API changes and Squat rewrite. Squat is still missing expunge handling. --HG-- branch : HEAD

Handle NOT in search without returning wrong results. --HG-- branch : HEAD

Changed .h ifdef/defines to use <NAME>_H format. --HG-- branch : HEAD

Don't crash if another search is started while we're still building the index for the first search. --HG-- branch : HEAD

Separate headers and body in building and searching. Added support for Lucene to index/search them separately. --HG-- branch : HEAD

Added lock/unlock backend operations. --HG-- branch : HEAD

Added fts_backend_expunge_finish() virtual backend function. --HG-- branch : HEAD

ADd support for expunges --HG-- branch : HEAD

Added fts_backend_get_last_uid() which is first used to check if build_init() needs to be called. --HG-- branch : HEAD

Let FTS backend init function take a struct mailbox instead of path. --HG-- branch : HEAD

API updates and some fixes --HG-- branch : HEAD

Added full text search plugin framework. Still missing support for handling expunges. Also it could use better logic with more complex SEARCH queries to figure out when the FTS index should be used. --HG-- branch : HEAD