Support build srs-librtmp by VS2015. 2.0.267
Support build srs-librtmp by VS2015. 2.0.267

ossrs/srs,ossrs/srs,winlinvip/srs,winlinvip/srs,ossrs/srs,ossrs/srs,ossrs/srs,ossrs/srs,winlinvip/srs,winlinvip/simple-rtmp-server,winlinvip/srs,winlinvip/srs,winlinvip/srs