Allow better filtering with IP address and File handle

Allow better filtering with IP address and File handle

To allow filtering by the client's IP address,
the addr_from_rqst_str() function was added which
extracts the IP address from incoming procedures
and converts them into a character string. Calls to
addr_from_rqst_str() were added to the top of each
probe so callers of the probes can use the IP addresses
as a filter.

Calls to __svc_fh() were also sprinkled were needed
so callers can also filter on file handles

Signed-off-by: Steve Dickson <steved@redhat.com>