HTML5: restructuring the client's html

Removing all the styling from the javascript files, it should all be done
in the css. Not finished yet, the chat and login screens still need a lot
of work.
HTML5: remaking the html markup for the chat

A lot of changes to make it easier to control the design from the css.
The actions in the chat now only add or remove classes from the elements instead
of changing their css, so the css is responsible for showing or hiding them
and controlling how they appear in the screen.
HTML5: pushing layout changes from @tylercopeland
HTML5: cleanup session whiteboard view, remove whiteboard controls

Removed the controls that are not used anymore, are gonna be used only when
the html5 is allowed to be a presenter.
Merge pull request #292 from daronco/html5-bridge-layout-setup

HTML5 new HTML markup and design