feat(list): reordering scrolls page, reordering performance better

Fixes #521. Reordering now uses webkitTransform instead of
element.style.left.  Additionally, as you drag the drag-element to the
top or bottom of the scroll-area, it will scroll it up or down as
allowed.

Refactors necessary: Common code from `<content>` and `<scroll>` moved
into js/ext/angular/controllers/ionicScrollController.  Then `<content>`
and `<scroll>` expose the controller, and `<list>` can require it.

`<list>` then uses the controller (if exists) to pass the scrollView and
scrollEl to ReorderDrag, and ReorderDrag uses that to scroll.

Additionally, js/ext/angular/test/controller/ionicScrollController tests
much functionality that was untested before.

js/ext/angular/test/controller/ionicScrollController.unit.js

@@ -0,0 +1,90 @@
+describe('$ionicScroll Controller', function() {
+
+  beforeEach(module('ionic.ui.scroll'));
+
+  var scope, ctrl, timeout;
+  function setup(options) {
+    options = options || {};
+
+    options.el = options.el || document.createElement('div');
+
+    inject(function($controller, $rootScope, $timeout) {
+      scope = $rootScope.$new();
+      ctrl = $controller('$ionicScroll', {
+        $scope: scope,
+        scrollViewOptions: options
+      });
+      spyOn(ctrl.scrollView, 'run'); // don't actually call run, this is a dumb test
+      timeout = $timeout;
+    });
+  }
+
+  it('should set this.element and this.$element', function() {
+    setup();
+    expect(ctrl.element.tagName).toMatch(/div/i);
+    expect(ctrl.$element[0]).toBe(ctrl.element);
+  });
+
+  it('should register scrollView as this.scrollView', function() {
+    setup();
+    expect(ctrl.scrollView instanceof ionic.views.Scroll).toBe(true);
+  });
+
+  it('should register controller on element.data', function() {
+    setup();
+    expect(ctrl.$element.controller('$ionicScroll')).toBe(ctrl);
+  });
+
+  it('should run after a timeout', function() {
+    setup();
+    timeout.flush();
+    expect(ctrl.scrollView.run).toHaveBeenCalled();
+  });
+
+  it('should not setup if no child .scroll-refresher', function() {
+    setup();
+    expect(ctrl.refresher).toBeFalsy();
+    spyOn(ctrl.scrollView, 'activatePullToRefresh');
+    timeout.flush();
+    expect(ctrl.scrollView.activatePullToRefresh).not.toHaveBeenCalled();
+  });
+
+  it('should work with .scroll-refresher child and proper refresher', function() {
+    var startCb, refreshingCb, doneCb, refresherEl;
+    setup({
+      el: angular.element('<div><div class="scroll-refresher"></div></div>')[0]
+    });
+    spyOn(ctrl.scrollView, 'activatePullToRefresh').andCallFake(function(height, start, refreshing, done) {
+      startCb = start;
+      refreshingCb = refreshing;
+      doneCb = done;
+    });
+    
+    scope.onRefresh = jasmine.createSpy('onRefresh');
+    scope.$parent.$broadcast = jasmine.createSpy('$broadcast');
+    var refresher = ctrl.refresher;
+
+    timeout.flush();
+
+    expect(refresher.classList.contains('active')).toBe(false);
+    expect(refresher.classList.contains('refreshing')).toBe(false);
+
+    startCb();
+    expect(refresher.classList.contains('active')).toBe(true);
+    expect(refresher.classList.contains('refreshing')).toBe(false);
+
+    refreshingCb();
+    expect(refresher.classList.contains('active')).toBe(false);
+    expect(refresher.classList.contains('refreshing')).toBe(false);
+
+    expect(scope.onRefresh).not.toHaveBeenCalled();
+    expect(scope.$parent.$broadcast).not.toHaveBeenCalledWith('scroll.onRefresh');
+
+    doneCb();
+    expect(refresher.classList.contains('active')).toBe(false);
+    expect(refresher.classList.contains('refreshing')).toBe(true);
+    expect(scope.onRefresh).toHaveBeenCalled();
+    expect(scope.$parent.$broadcast).toHaveBeenCalledWith('scroll.onRefresh');
+  });
+
+});