ipcc: Have a few goes at tidying up after a dead server (#434)

This is an attempt to make sure that /dev/shm is cleaned up when a
server exits unexpectedly. Normally it's the server's responsibility
to tidy up sockets, but if it crashes or is killed with SIGKILL then
the client (us) makes a reasonable attempt to tidy up the server sockets
we have connected. The extra delay here just gives the server chance to
disappear fully. As a client we can get here pretty quickly but shutting
down a large server may take a little longer even when SIGKILLed.
The 1/100th of a second is an arbitrary delay (of course) but seems to
catch most servers in 2 tries or less.