Add callback to register a LateWin handler from Javascript
Merge pull request #145 from rtbkit/LATEWIN

Add callback to register a LateWin handler from Javascript
Add support for metro field in BidRequest and OpenRTBBidRequest
Merge pull request #146 from rtbkit/MetroDMA

Add support for metro field in BidRequest and OpenRTBBidRequest
Merge remote-tracking branch 'upstream/master'