Adding diagnostics property to rygel.conf. The property is disabled by default.
CVP2RI-333 : don't report root container in child count, where parent and upnp_id are both 0.
Adding alternate path for virtual protocol if dlna+ prefixed protocol is not supported in gstreamer
Checking for WritableContainer instance just before trying to add a reference.
Merge branch 'cablelabs/master' of github.com:cablelabs/rygel into cablelabs/live-streaming
Cleaning up various live streaming config variables

Changed the rygel.conf OdidMediaEngine live control settings to
 "live-sim-start-mode" and "live-sim-autoreset-time".

Changed units of most of the variables to seconds.

Now debug logging the various config variables when utilized.

Sim autoreset now honors the live-sim-autoreset-time setting.

Fixed a bit of unit confusion in ODIDUtil.advance_index_to_offset()
 and usec_to_secs(). The issue was limited to logging and variable
 names. But got it cleaned up - added msec_to_secs().

Ran with various config variable settings and confirmed changes had
 desired effects.