Updated mediawiki/extensions
Project: mediawiki/extensions/MathSearch  b72f2218a6cbf294eef1409f45e7a7e6c44c8f5e

Prepare for DB2 integration

* new concept of MathEngine in backend
* seperate frontend and backend to prepeare for performance benchmark

Change-Id: I4f967a91fd409fea7d55a4a0fa3912aac958c222