Added setBackgroundColor, inspired by issue #11
Added setBackgroundColor, inspired by issue #11

happy-tanuki/GrowingTextView,ywzw2013/GrowingTextView,zuojx1013/GrowingTextView,alexeylang/GrowingTextView,perrystreetsoftware/GrowingTextView,Meihualu/GrowingTextView,shenhzou654321/GrowingTextView,HansPinckaers/GrowingTextView,mabuward90/GrowingTextView,Kingside/GrowingTextView,jagreenwood/GrowingTextView