Task.jsm allows not only generators but also iterators to be yielded,
using ``typeof yielded == 'Function'`` as the test for an iterator, but
since the Q promise includes a send() method, yielding a Q promise
instead of a Mozilla promise results in an infinite loop. To fix this,
we disable Q's send() method, which is just an outdated synonym for
invoke() anyway.
This will have to be done every time we update Q until send() is
removed, Task.jsm is changed, or we stop using Task.jsm with Q promises.
55f044f87a