PetitParser has a PPContext in newer versions but the GST code
is older and doesn't have it. Provide an alternative impl.
Provide >>#do: for the SIPVia for Pharo to print the data
Avoid importing MIMERWStream as it is dead in Pharo
* Change the category for the tests and extensions
* Rewrite usages of >>nl and >>cr
* There are still issues with the Socket code, Datagram handling
and and expands.