Currently only GetTextFaceA is tested, and in an ancillary way, and the
behavior differs from GetTextFaceW.

If the the socket is connected and lpFrom is not NULL, Linux will set
msg_namelen to zero and ignore msg_name in recvfrom so don't try try
to update lpFrom.

This allows applications to wait for state transitions to be really
complete. Fixes some xvid crashes.

Prevents a null pointer dereference.

Should fix Valgrind warnings 'Conditional jump or move depends on
uninitialised value(s)' in inetcomm tests.

The conformance needs to be added on to the offset in the buffer so
set this before calling each the writer of each class of pointer
description in write_pointer_description.

Pass the passed in offsets to buffer and memory to
write_pointer_description_offsets in
write_varying_array_pointer_descriptions.

rpcrt4: Use abrtitrary pointer identifiers when marshalling pointers instead of using pointer values.

This ensures that no information about the server memory layout is
leaked to clients.

Free the memory associated with the field and value of the custom
header otherwise it will be leaked. Found by Valgrind.

This ensures that it's also done correctly when a read from the pipe
returns EOF.