Changed DTCustomColoredAccessory to include DTCustomColoredAccessoryTypeSquare

Changed DTCustomColoredAccessory
	Added DTCustomColoredAccessoryTypeSquare to
DTCustomColoredAccessoryType
	Added method squareAccessoryWithColor:backgroundColor:
	Added properties frontSquareAccessoryColor,backSquareAccessoryColor

Wanted an image that I could use to signify that the menu option would
present a view controller modally using the entire screen