install: update dependencies, patch bbb-conf, set BBB base-url in freeswitch vars.xml and bbb-webrtc-sfu default.yml

- use luasocket and luasec for http requests which are available as
  ubuntu packages
- having BBB base url configurable makes deployment w/ external
  freeSWITCH servers easier

- add additional authorization endpoints in o.b.w.c.ConnectionController
- query this endpoint in freeswitch dialplan script
- query this endpoint in bbb-webrtc-sfu AudioManager
- add prebuilt bbb-web classes for easy installation
- update install script to deploy all fixes