OSMF SVN

Fix FM-1087.

Attempted fix for FM-1022: Streaming connections fail on networks that block RTMP. The fix is as follows:
1) Prioritize RTMPT over RTMPS.
2) Increase the connection attempt interval from 50ms to 200ms.
3) Add an undocumented property on NetConnectionFactory named "connectionAttemptInterval", which can be used to override the default of 200ms.

Add layout direction attributes to work around bug SDK-26940, when in Flex 3 compatibility mode.

Fix bug 1041. This is not a timeout issue, rather it is a bug within the NetNegotiator which will only manifest itself when a NetConnection takes more than 50 ms to connect.

Fix FM-981: MAST plugin doesn't show preroll for SMIL resources.

Fix FM-982: MAST plugin doesn't show preroll for F4M resources.

Addition to fix for FM-936: Add null check when casting to NetStreamTimeTrait, since DVR elements will have a TimeTrait of a different type.

1. Remove unnecessary logic from MulticastNetLoader.as
2. Fix FM-1072
3. Fix FM-1081

Fix for FM-931

Fix FM-936: RTMP preroll briefly shows image when in SerialElement and rewound. The fix is to call Video.clear() whenever a VideoElement initiates a seek to the end. Because a seek within a SerialElement applies to all children (e.g. seek to the end causes all children to seek to their ends), we can ensure that each child's Video is cleared as soon as the playhead moves past its endpoint, so that the image is not displayed when the playhead returns to that child (through a seek or a rewind).