Merge pull request #32 from lowe/alttab

reset modifiers to false on window focus. fixes alt+tab, tab switching, and related issues

keymaster.js

@@ -94,6 +94,14 @@
     }
   };
 
+  function resetModifiers() {
+    for (k in _mods) {
+      if (_mods.hasOwnProperty(k)) {
+        _mods[k] = false;
+      }
+    }
+  }
+
   // parse and assign shortcut
   function assignKey(key, scope, method){
     var keys, mods, i, mi;
@@ -144,6 +152,9 @@
   addEvent(document, 'keydown', dispatch);
   addEvent(document, 'keyup', clearModifier);
 
+  // reset modifiers to false whenever the window is (re)focused.
+  addEvent(window, 'focus', resetModifiers);
+
   // set window.key and window.key.setScope
   global.key = assignKey;
   global.key.setScope = setScope;