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.
@kamenim: Historically, the macros were introduced to be close (mimic) Microsoft and Samba behavior. With time, it appeared that the macro checking for != success scope was not relevant enough or let's say had too many exception requirement to fulfill the job properly.

@kamenim: agreed to remove boolean comp whereas implemented but not convinced about the gain of migrating from direct comparison to macro.