Silence at least some Firefox console errors
Silence at least some Firefox console errors

This is all due to the stupid un-addressed bug here: https://bugzilla.mozilla.org/show_bug.cgi?id=712329

This patch does as much as we can to silence these errors, but it's still far
from a complete fix. Unfortunately I don't think we can do much more.
Responding by moving away from websockets seems absurd.

Closes #24

cortesi/devd,cortesi/devd,cortesi/devd,cortesi/devd