[sink-input-ext] Add support for re-classifying othermedia streams.
[dbusif] Reclassify streams after new client is registered.
[config-file] Reduce log level of missing extra config directory.
[sink-input-ext] Set stream flags to sink-input in handle_new_sink_input().

When this function is used for re-classifying streams, need to apply
stream flags -hack here as well.
[module] Support overriding default group from configuration.
[sink-input-ext] Extend stream corking.

Previously, corking was applied when group with corking enabled was
selected. After this, if the group changed to a group which didn't have
corking enabled, corking was never lifted.

To properly implement both corking and uncorking of streams,
policy-enforcement-module needs to follow the corking state of the
streams it manages so that streams corked by users request aren't
uncorked when the group changes.

As small optimization, if pa_sink_input_ext_cork() is never used, don't
follow streams corking state.
Merge pull request #12 from jusa/reclassify

Add support for reclassifying streams and overriding default othermedia configuration.