Fix #183 avoiding that the html tags inside the javascript being understood as part of the html page

send alert messages to an events channel when a channel is created or destroyed and when a client subscribe or unsubscribe a channel

Otherwise no output is visible.

Since chrome updated to version 38 it states 'WebSocket.URL' is deprecated. Please use 'WebSocket.url' instead.

add push_stream_header_template_file directive to be possible store the header template in a different file

Signed-off-by: Wandenberg <wandenberg@gmail.com>

publish the message to all connected channels in javascript sendMessage function like when using websocket connection