Looks like nondeterminism in `next(d.iterkeys())` was breaking
consistency with A&B. Next up: switching determinism on or off.

Had a dumb translation error

Some tests are disabled and forcing outcomes does not work

Dunno why it was ever `complex`

Added some more terms to clifford.by_name to ease lookup of complex
conjugates

Added GraphState.toggle_edges(), used by GraphState.measure_x

Nearly finished GraphState.measure_x

Next up: measurement
Also added a test on local complementation