Updated copyright notices to include the year 2018.

Updated copyright notices to include the year 2017.

lib-fts: fixup misuse of hash_table_insert() Instead use hash_table_update() to replace value when a key exsists.

lib-fts: Improved stopword file reading. The reading tries to be a little bit stricter now. Only stopwords at the start of a new line are accepted now. Changed fi stopwords accordingly. Also removed superfluous stack allocation in parsing.

global: freshen copyright git ls-files | xargs perl -p -i -e 's/(\d+)-201[0-5]/$1-2016/g;s/ (201[0-5]) Dovecot/ $1-2016 Dovecot/'

lib-fts: fts-filter API changed to have a non-pointer vfuncs variable. The main benefit being that the fts-filter implementations can save a few lines of code.

lib-fts: Include fts-filter.h in fts-filter-private.h This avoids having to always include them both.

lib-fts: Removed supports() function from filter API I think the original idea was that this could be used to automatically create filters for many languages, but this probably won't be needed or wanted.

lib-fts: Removed filter name macros from fts-filter.h The filters can be directly accessed via their class structs.

lib-fts: Various fixes and cleanups to stopwords filter. Most importantly words added to hash table needs to be allocated from the pool and not data stack.

lib-fts: Assume that fts_language.name is always lowercased and has two letters. Anything else just unnecessarily complicates the code.

lib-fts: Changed filter's internal APIs to return error_r directly. It's not very safe to store strings allocated from data stack to any permanent structs.

lib-fts: Delay stopwords filter full initialization until it's needed.

fts: Change filter API to be able to return errors Modify fts_filter_filter() to return integer status codes. It returns 1 if a token was returned, 0 if it was filtered away and -1 on error.

Initial import for lib-fts. Parts of what this code does was already implemented internally by fts-lucene. lib-fts is intended to be usable for all the FTS backends. The APIs are still going to change a bit, but hopefully not after v2.2.17 release. Mostly written by Teemu Huovila.