Close a substantial resource leak in drone processes.

Close a substantial resource leak in drone processes.

A drone inherits the transport_client of its parent process,
including a socket and a substantial amount of memory.  The
old code avoided freeing the transport_client in order to
avoid disconnecting the parent from Jabber.

The new code contrives to reclaim the resources without
sending a disconnect to Jabber.  Hence the parent remains
connected.

M    include/opensrf/transport_client.h
M    include/opensrf/transport_session.h
M    src/libopensrf/osrf_system.c
M    src/libopensrf/transport_session.c
M    src/libopensrf/transport_client.c

git-svn-id: svn://svn.open-ils.org/OpenSRF/trunk@1890 9efc2488-bf62-4759-914b-345cdb29e865