regression fix: invalid pidfile location

closes: https://github.com/rsyslog/rsyslog/issues/86
Merge branch 'v7-stable' into v8-stable
bugfix: file descriptor leak with Guardtime signatures

When a .gtstate file is opened it is never closed. This is especially
bad when dynafiles frequently get evicted from dynafile cache and be
re-opened again.
testbench: support environments with limit on nbr of open sockets
Merge branch 'v7-stable' into v8-stable
Merge branch 'v8-stable'