Graphical upgrade

After the great presentation of @bdepaula showing the Cylc GUI, I noticed some desire from the team to have a more friendly and aesthetic GUI.

So, I took a little time to mock up a better Home page style to start the discussion about the importance of making an upgrade to the GUI soon.

@mcastril what do you think about this? I know that this is not a priority nowadays, but might be relevant sooner or later.