feat(tap): Make TAP_RELEASE_TOLERANCE configurable

Setter for TAP_RELEASE_TOLERANCE so the default can be changed. Closes
#1362

Author: Adam Bradley

Diff for: js/utils/tap.js

@@ -232,6 +232,10 @@ ionic.tap = {
       }
     }
     return false;
+  },
+
+  setTolerance: function(val) {
+    TAP_RELEASE_TOLERANCE = val;
   }
 
 };