Fix globcnt is zero crash

I have hit this crash while trying to import a PST file.
Pull request went out to become somewhat big (I ended up here while trying to isolate while the crash).
The cherry on the top of the cake is actually the last patch - 13d7bbc1783d8348df7c63b2b062bedb2881a15e
(at least this fixed the problem for me)

It turned out we initializing TDB backend for Indexing while every other backend defaults to MySQL.
I this this is widely untested combination and also undesired :)

Please review!

Please also note that this pull request is superset for #90
So we should either merge this one and discard #90 OR merge #90 first and the I will clean up this
request to contain only distinct patches.
__location__ is __FILE__:__LINE__ so here we have __FILE__:__LINE__:__LINE__

actually I'd like to decide which format should we use, until now I've been using __function__:__LINE__ because normally I identified more easily the context with function name than filename, but I'm not sure the best choice (or if every debug line should have that)