Re-style keyboard to look more like native Apple emoji keyboard. Move 'delete' key from scrollView page to the segmentControl. Make switching categories and scrolling pages faster by being smarter about reusing pages and buttons. Show message when Recent category is empty. Add method for clearing Recent emoji history. Remove log statements.
Add hint label to Recent category.
Tweak 'recently used' label style.
Fixes logic for initial selected category so that if there are no Recent emoji yet, it defaults to the next tab (Faces) instead.
Merge remote-tracking branch 'jmascia/master'

Fix build issues and change to ARC
Conflicts:
	EmojiKeyBoardView.m