Factor in scrolling offset to blockly trace arrow
Merge pull request #319 from virtual-world-framework/trace-fixes

Blockly trace fixes
Adds new VO, fixes a minor bug with removing an object from the grid.
Start on right scenario.
Merge pull request #323 from virtual-world-framework/vo-revision-2-3

New VO, bug fix for removing an object from the grid.
Ken McClure:  update to rover tracks.  Added in the two turns.
Ken McClure: update to small rocks along mini rover pathway.
remove track offset
Merge pull request #315 from virtual-world-framework/Ken-Art

Update to mini rover tracks.
Start adding main menu
Added overlay
Play intro video after play game is clicked