Add --with-rundir configure flag

This allows use of /run on tmpfs instead of /var/run
without downstream symlink magic or patches.
Merge pull request #17 from rworkman/rundir

Add --with-rundir configure flag
Fix for GLib-CRITICAL: Source ID was not found

On remote ck session, there was a warning generated during log out.
This patch should fix that warning as well as add a couple debug
lines to help future troubleshooting. Thanks to hhoffstaette for
helping to troubleshoot this issue. For details see:
https://github.com/ConsoleKit2/ConsoleKit2/pull/15