Show a green play arrow for missions that you can launch from the storyboard.

If a mission clickzone does not have an onClick function, a gray arrow will be used.
Descriptions for missions in the storyboard now stay on screen when the mouse leaves the clickzone.
Ability to zoom in and out and translate in the storyboard.
Added scenes for second Dyson Outpost in mission 1
Plug second Dyson outpost into storyboard.
Refactor: load new game scenes automatically from the chapters directory
Plug in third leg of mission one