Support optional methods of delegates.
Fix selectors comparison.
UITextField+DelegateBlocks: fix typo.
MFMailComposeViewController: fix wrong method signature.
Remove depricated UIAccelerometer methods.
UIAlertView+DelegateBlocks: blocks were not called because iOS checks respondesToSelector: at the time when delegate is set (and before delegate blocks are set).
UIActionSheet+DelegateBlocks: the same issue like with UIAlertView.