OwrWindowRegistry: Implement registry for mapping tag to window handle

This is just a hash table wrapper with API. The OpenWebRTC API user will
be expected to register tags against window handles before renderers are
created. When the renderer is created, a tag is passed to its
constructor. This tag can then be used to look up the window handle the
renderer is supposed to render into.
OwrVideoRenderer: Make use of the tag=handle window registry

The window handle is looked up from the window registry. If none is
found, the renderer will create its own window, which preserves the
previous default behaviour. Otherwise the window handle will be set on
glimagesink and glimagesink will render into that widget.
Update scripts

Some improvements to robustness and behaviour of the scripts
bridge: daemon -> openwebrtc-daemon

Use a less generic name since this can be installed to /usr/bin
Do weak-linking to VideoToolbox for iOS

This way we will get hardware codecs on iOS8+ but still can
run on devices using an older version of iOS.
Fix libtool to work properly with -weak_framework linking
local: Don't set 0 as maximum framerate if none is given

That's going to cause an assertion, the valid range is [1,MAX]. Also
don't plug a videorate element at all if the maximum framerate is
given as 0.
Update scripts

Patch libnice to significantly reduce time taken for ICE/DTLS connection
establishment
Add link to openwebrtc-examples
Update scripts

Fix possible double free in libnice
transport: Don't put a capsfilter after the audio decoder and link the depayloader

We can't just force the audio decoder to output something specific, this will
fail with most audio decoders out there... and if conversion is required we
will do that later already.

Also make sure the pad that is ghosted is the decoded_valve and not the
capsfilter, which is incorrect.
sdp: Allow a=rtcp address to be optional

In accordance with RFC 3605
bridge: Don't assume mdesc.rtcp exists when checking mdesc.rtcp.mux
domutils: Use the expected variable name
webrtc_js: Avoid assigning the same property twice
peerhandler: Set the TURN server transport type from the iceServer URL

In accordance with RFC 7065