Convert search-engine to AMD. Breaks all code.

The remainder of the code hasn't been re-designed for this, so it just
soft of ... hangs there.
Add default 'make test'-target.
Implement requirejs in core app.

It can do actual searches again, but scoring/sorting results and google
analytics is broken big time.
Speed up slow unit-test.
Fix search scoring and limiting.
Re-integrate jQuery in the good old way.
Re-add Google Analytics.