UIView is now used instead of UIWindow, this should prevent cases where the key window was not properly restored after dismissing TPComposeView. Initial displayed text can now be changed after initialization, which allows for re-use of the same TPComposeView with different text. Character limit is no longer applicable if the TPComposeView is not editable, this prevents the case where the initial text is longer than the max characters and disables the _composeButton (the only available button when editable == NO).