added start scene

with buttons/images
added buttons

some whimsy and text.
1st button
"did you know you can fly?"
2nd button
"the hardest part isn't learning to fly but believing you can fly"
adjustin' buttons and adding the 2d  tool kit
Merge branch 'robert-unity43'
remove 2-d tool kit

see above
Merge branch 'master' of https://github.com/robertsdionne/nightwitches

Conflicts:
	Assets/MainScene.unity
	Assets/scripts/AirplaneController.cs
	Assets/scripts/PopulateTargets.cs
Fix merge conflicts.
Changes for bombs and explosions.