Update Layout Examples to ASDK 2.0 (#2551)

* Objective-c project updated to ASDK 2.0

* fix assets error

* [LayoutSpecExamples] Renamed new example project to be easier to type / find.

* [Bulid] Manually create Sample.xcscheme file to hopefully fix complaining bulid :).

* clean up project

* commentary on ASAbsoluteLayoutSpec

* address @maicki's comments

examples/LayoutSpecExamples/Sample/OverviewViewController.m

@@ -0,0 +1,75 @@
+//
+//  OverviewViewController.m
+//  Sample
+//
+//  Copyright (c) 2014-present, Facebook, Inc.  All rights reserved.
+//  This source code is licensed under the BSD-style license found in the
+//  LICENSE file in the root directory of this source tree. An additional grant
+//  of patent rights can be found in the PATENTS file in the same directory.
+//
+
+#import "OverviewViewController.h"
+#import "LayoutExampleNodes.h"
+#import "LayoutExampleViewController.h"
+#import "OverviewCellNode.h"
+
+@interface OverviewViewController () <ASTableDelegate, ASTableDataSource>
+@property (nonatomic, strong) NSArray *layoutExamples;
+@property (nonatomic, strong) ASTableNode *tableNode;
+@end
+
+@implementation OverviewViewController
+
+#pragma mark - Lifecycle Methods
+
+- (instancetype)init
+{
+  _tableNode = [ASTableNode new];
+  self = [super initWithNode:_tableNode];
+  
+  if (self) {
+    self.title = @"Layout Examples";
+    self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStylePlain target:nil action:nil];
+    
+    _tableNode.delegate = self;
+    _tableNode.dataSource = self;
+    
+    _layoutExamples = @[[HeaderWithRightAndLeftItems class],
+                        [PhotoWithInsetTextOverlay class],
+                        [PhotoWithOutsetIconOverlay class],
+                        [FlexibleSeparatorSurroundingContent class]];
+  }
+  
+  return self;
+}
+
+- (void)viewWillAppear:(BOOL)animated
+{
+  [super viewWillAppear:animated];
+  
+  NSIndexPath *indexPath = _tableNode.indexPathForSelectedRow;
+  if (indexPath != nil) {
+    [_tableNode deselectRowAtIndexPath:indexPath animated:YES];
+  }
+}
+
+#pragma mark - ASTableDelegate, ASTableDataSource
+
+- (NSInteger)tableNode:(ASTableNode *)tableNode numberOfRowsInSection:(NSInteger)section
+{
+  return [_layoutExamples count];
+}
+
+- (ASCellNode *)tableNode:(ASTableNode *)tableNode nodeForRowAtIndexPath:(NSIndexPath *)indexPath
+{
+  return [[OverviewCellNode alloc] initWithLayoutExampleClass:_layoutExamples[indexPath.row]];
+}
+
+- (void)tableNode:(ASTableNode *)tableNode didSelectRowAtIndexPath:(NSIndexPath *)indexPath
+{
+  Class layoutExampleClass = [[tableNode nodeForRowAtIndexPath:indexPath] layoutExampleClass];
+  LayoutExampleViewController *detail = [[LayoutExampleViewController alloc] initWithLayoutExampleClass:layoutExampleClass];
+  [self.navigationController pushViewController:detail animated:YES];
+}
+
+@end