Bug 901041 - Remove 'swipe left' screen in tutorial (as part of the first run experience)

Conflicts:
	apps/communications/ftu/css/images/tutorial/2@1.5x.png
	apps/communications/ftu/css/images/tutorial/2@2x.png
	apps/communications/ftu/css/images/tutorial/3@1.5x.png
	apps/communications/ftu/css/images/tutorial/3@2x.png
	apps/communications/ftu/css/images/tutorial/4@1.5x.png
	apps/communications/ftu/css/images/tutorial/4@2x.png
[Bug 903043] Fix and enhance e.me integration on the landing page
Bug 902465 - Too many CanvasLayer on e.me results hurts panning. part 1. r=vingtetun
Bug 902465 - Too many CanvasLayer on e.me results hurts panning. part2 r=ran
Bug 902465 - Too many CanvasLayer on e.me results hurt panning. r=ran
Bug 900989 - The height of homescreen pages force excessive repaints. r=ran
Bug 902897 - Prevent e.me to be scrolled while panning between pages. r=ran