Openchange jkerihuel/indexing sql

Merge all changes from openchange/openchange jkerihuel/indexing-sql into zentyal/openchange master. It includes:

- code review/refactoring of mapistore namedprops code
- bugfixing done during interop plugfest
- header review
- unit test built with automake/autoconf rather than cmake + additional changes (lack complete integration though)

WARNING: Applying this pull request requires to change openchange.conf.mas model to comply with the new model: MYSQL URL has been replaced with parametric options to fix and workaround URL parsing and errors.