Get rid of isClicked

It can be argued that everything should be derived from isDown and
position (the two real facts about the mouse), so maybe that is a
direction to go from here.

libraries/Mouse.elm

@@ -7,7 +7,7 @@ module Mouse where
 @docs position, x, y
 
 # Button Status
-@docs isDown, clicks, isClicked
+@docs isDown, clicks
 
 -}
 
@@ -31,11 +31,6 @@ True when the button is down, and false otherwise. -}
 isDown : Signal Bool
 isDown = Native.Mouse.isDown
 
-{-| True immediately after the left mouse-button has been clicked,
-and false otherwise. -}
-isClicked : Signal Bool
-isClicked = Native.Mouse.isClicked
-
 {-| Always equal to unit. Event triggers on every mouse click. -}
 clicks : Signal ()
 clicks = Native.Mouse.clicks

libraries/Native/Signal/Mouse.js

@@ -20,15 +20,12 @@ Elm.Native.Mouse.make = function(elm) {
     y.defaultNumberOfKids = 0;
 
     var isDown    = Signal.constant(false);
-    var isClicked = Signal.constant(false);
     var clicks = Signal.constant(Utils.Tuple0);
 
     var node = elm.display === ElmRuntime.Display.FULLSCREEN ? document : elm.node;
 
-    elm.addListener([isClicked.id, clicks.id], node, 'click', function click() {
-        elm.notify(isClicked.id, true);
+    elm.addListener([clicks.id], node, 'click', function click() {
         elm.notify(clicks.id, Utils.Tuple0);
-        elm.notify(isClicked.id, false);
     });
     elm.addListener([isDown.id], node, 'mousedown', function down() {
         elm.notify(isDown.id, true);
@@ -44,7 +41,6 @@ Elm.Native.Mouse.make = function(elm) {
         position: position,
         x:x,
         y:y,
-        isClicked: isClicked,
         isDown: isDown,
         clicks: clicks
     };