Jitsi Meet doesn't seem to work with c2s_require_encryption set to true.
c2s_require_encryption is false by default. However it is possible that
in some Prosody configurations it is overriden by a global config to be
true. In that case Jitsi Meet might not work out-of-box. So let's set it
explicitly to be sure it is correct.

Also clears debian package from including *.js files from source roote folder, files which were not used.

Now the web app can be installed separately from jicofo and jitsi-videobridge, or can be installed on machine running nginx or apache. Currently only nginx will be configured and apache config is left to user. Later we can add and the apache config. Renames jitsi-meet to jitsi-meet-web (just the web content) and jitsi-meet-web-config (configuring jetty, nginx or apache). A new jitsi-meet package will be introduced, a meta package depending on jicofo, jvb and the current packages.