We now emit a signal (djblets.webapi.signals.webapi_token_created)

when we generate a token via WebAPITokens.objects.generate_token()

method. In addition, this method now takes an auto_generated parameter

to indicate whether or not the created token is being automatically

generated by some process (such as an integration). This can be used by

signal consumers to determine, e.g., whether or not an e-mail should be

sent upon token generation.

Ran /r/9285/ unit tests.