Store the current room in the sessionStore

If there is no room specified in the session store then look for one in
the URL query string. If there is not one in the query string then
create a new room.
Share the query string between presentations

Because the default presentation uses the query string to show differnt
transitions and themes this checks for a change in the query string and
communcates it to the other presentations to ensure syncronization.
Temporary hack to display the sharing URL.

Hook the Ctrl+g keypress to pop up a dialog box to display the sharing
URL for the presentation.
Merge branch 'master' of github.com:gordienoye/go-reveal