Make encoder settings configurable

[mekya]

Parameters to configure via properties file
Generic

• encoder : Name of the encoder. X264, openh264, h264_nvenc. If it's unset, use hardware encoder if available by default.
• preset
• profile
• level
• rc
• encoder_specific: encoder specific parameter. It will be used if encoder supports like x264params

[The-Code-Monkey]

@mekya how would i change the encoder settings if i wanted to do it manually for the WebRTCApp, because in the red5-web.properties file there is a settings.encoderSettingsString how do i change that and what will it do if i do