Ensured that pressing Modifiers+Key/ExtKey does not produce an event with just the Key/ExtKey.

area.go

@@ -168,6 +168,8 @@ type KeyEvent struct {
 	// was pressed. Key and ExtKey will not both be nonzero.
 	ExtKey		ExtKey
 
+	// (TODO Modifiers alone needs to be figured out)
+	// If a Key or ExtKey is pressed with modifiers held down, then a KeyEvent with only Key/ExtKey and no Modifiers WILL NOT be sent, but a KeyEvent with only Modifiers and no Key/ExtKey WILL.
 	Modifiers		Modifiers
 
 	// If Up is true, the key was released; if not, the key was pressed.

todo.md

@@ -9,7 +9,6 @@ super ultra important things:
 	- in general, figure out what to do on multiple events, period
 - OS X: handle Insert/Help key change in a sane and deterministic way
 	- will need old and new Mac keyboards...
-- should pressing modifier+key in the keyboard test mark the key alone as pressed as well? I'm leaning toward no, in which case make sure this behavior exists on all platforms
 - make sure MouseEvent's documentation has dragging described correctly (both Windows and GTK+ do)
 	- fix OS X so that it follows these rules
 - cap click count to 2 on all platforms