The names of groupchats are truncated internally to 22 characters.
This causes many problems with groupchats, since spectrum incorrectly
identifies the chat by the long name.
To overcome this the phoneNumber-unixTime is converted to hexadecimal,
to shorten the groupchat below 22 characters
Spectrum2/backend.py:handleDataRead is called when transwhat receives
data from Spectrum. The parameter `data' contains multiple (or pieces
of) WrapperMessages. Instead of passing all the data to
wrapper.ParseFromString. We should only pass a single WrapperMessage.
When a whatsapp buddy sends an image, video or sound to the spectrum
user, the spectrum user will receive a URL that links to the media.
FileTranfer in spectrum is not working, apparently. Thus media cannot be
sent yet.
