Initial prototype for mwsindex

Summary:
I named it mwsindex2 because there is already a mwsindex in
mws/src/mws/index/CMakeLists.txt . How to deal with it?
Not sure if heading the right way with
a) the mwsindex exe itself
b) configuration of the cmake files

Test Plan: no test plan

Reviewers: cprodescu

Reviewed By: cprodescu

Differential Revision: http://phab.code4fun.de/D27