First attempt at an implementation of a non-blocking shared port client.
Fix handling of NULL char *; fix non-blocking logic. #4094
Mark socket as non-blocking when a connection attempt is made. #4094

This causes clients to be rejected as soon as the daemon's backlog
is hit.  This is equivalent behavior to the case where the daemon
is listening on the network and the TCP socket backlogs.
ifdef out portions which will not compile under Windows. #4094
Merge branch 'master' into shared_port_nonblocking
Merge branch 'master' into shared_port_nonblocking
Merge branch 'master' into shared_port_nonblocking
Merge remote-tracking branch 'github/shared_port_nonblocking' into shared_port_nonblocking
Attempt to make the shared port transparently forward collector connections.
Allow shared port to peacefully coexist with the collector. #0
Have COLLECTOR_USES_SHARED_PORT do the requisite configuration. #3813
Merge branch 'master' into V8_1-vc-branch
Merge remote-tracking branch 'origin/V8_1-vc-branch' into V8_1-vc-branch
Document #4341
Merge branch 'V8_2_0-branch' of /p/condor/repository/CONDOR_SRC into V8_2_0-branch

Conflicts:
	doc/version-history/8-2.history.tex
Merge branch 'V8_2_0-branch' of /p/condor/repository/CONDOR_SRC into V8_2_0-branch
Merge branch 'V8_2_0-branch' into V8_2-branch
minor 8.2.0 version history item edit. #4341
Document #4370
updates to the upgrading from 8.0 to 8.2 section of the version history