Set config.use_mwparserfromhell to True by default

I've been running with this for a while now, and haven't run
into any issues. It probably won't change anything for most users,
but for those with the library already installed, they'll see
a small performance boost.

Change-Id: Id088a84fa7d69053713cccb4c12995eaff3220ff
Merge "Set config.use_mwparserfromhell to True by default"