HTTP API kickoff client

[winlinvip]

@see #406

[winlinvip]

Provide API to support kicking off the stream.

TRANS_BY_GPT3

[winlinvip]

Usage instructions, refer to WIKI:
https://github.com/simple-rtmp-server/srs/wiki/v2_CN_Security#kickoff-client
https://github.com/simple-rtmp-server/srs/wiki/v2_EN_Security#kickoff-client

https://github.com/simple-rtmp-server/srs/wiki/v2_CN_HTTPApi#kickoff-client
https://github.com/simple-rtmp-server/srs/wiki/v2_EN_HTTPApi#kickoff-client

TRANS_BY_GPT3

[winlinvip]

Actually, the client for live streaming should be deleted.

TRANS_BY_GPT3