Added rtmp.proxytype config option

We have what should be a small change needed to latest JW Player so that it can work better with RTMPS. We need some way for the user to be able to set the NetConnection.proxyType:
 
NetConnection.proxyType="best"
 
For RTMPS it will then do RTMP over SSL rather than RTMPT over SSL which as you know works much better. The docs are here:

http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/net/NetConnection.html#proxyType

The default is "none". With this value set any RTMPS connection will be RTMPT over SSL. If proxyType is set to "best" then it will try to negotiate a RTMP over SSL connection. Which is much better. I am pretty sure if it can't it will default back to RTMPT over SSL. We just need some way for the customer to set the proxyType value through the player code.