Switch from "macauth" to "hawkauth" for authentication.
Update noncecache tests for hawkauthlib semantics.

Hawk has much simpler timestamp-handling than macauth; it's just a
simple cache of previously-seen (timestamp, nonce) pairs and a static
window outside which timestamps are rejected.
Ignore *.egg files
fix typo in warning message
Use simplejson for memcached serialization, if available.

It has better behaviour for slightly-non-standard python instances
like decimal.Decimal.
Merge pull request #28 from mozilla-services/rfk/hawkauth

Update to use hawkauth (Bug 960876, r=telliott)