Merge pull request #18 from michael-erasmus/master

cgcolor sugar method
more idiomatic
don't cache mutable objects
default frame should not assume iphone
cgcolor helper for a more idiomatic sugarcube
fixes to UIActionSheet
updated README
more idiomatic
don't cache mutable objects
default frame should not assume iphone
extend NSArray instead of Array
string += uinib method
'nil' doesn't play well with NSUserDefaults (expects NSNull.null, which doesn't play well with rubymotion).  store 'false' instead
UIView#controller method - uses nextResponder
UITextField#to_s
make _after_proc prettier
add generic UIView#animate method - used by 'move_to' and 'fade_out'
move 'assign' into animate, and make block optional
move UIView#animate into a class method UIView##animate
added 'isFirstResponder' to UITextField#to_s