Replace keypress with other events

[Björn Weinbrenner]

According the official W3C specification the event 'keypress' is deprecated (​http://www.w3.org/TR/DOM-Level-3-Events/#event-type-keypress). Some modern mobile browsers (Android, Windows) don't support this event. Alternative events are keydown, keyup, input or textInput (supported by some browsers but not specified), beforeinput (specified but not supported by browsers). CKEditor uses keypress at some places and causes problems on mobile devices. One place is the UndoManager (plugins/undo/plugin.js) so that the 'change' event isn't fired properly on mobile devices.

			editor.editable().on( 'keypress', function( event ) {
					undoManager.type( event.data.getKey(), 1 );
				} );

[Jakub Ś]

DUP of #10926