Converts the PortCfgPointer to reference counted

Converts the PortCfgPointer to reference counted

This allows long-lived connections to retain access to their original
receiving port configuration even after squid has been reconfigured.
Reference counting prevents some leaking of these port configuration
details and associated state by removing locking uncertainties.

Also, fixes all parsing errors resulting from the change. Most of
the issues were due to use of raw-pointers and explicit
cbdataReference*() API.