Merge branch 'master' into update-objc

Conflicts:
	AsyncDisplayKit/ASDisplayNodeExtras.h
	AsyncDisplayKit/Details/ASTextNodeRenderer.h
	AsyncDisplayKit/Details/ASTextNodeShadower.h

AsyncDisplayKit/TextKit/ASTextNodeWordKerner.h

@@ -0,0 +1,33 @@
+/* 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 <Foundation/Foundation.h>
+#import <UIKit/NSLayoutManager.h>
+
+NS_ASSUME_NONNULL_BEGIN
+
+/**
+  @abstract This class acts as the NSLayoutManagerDelegate for ASTextNode.
+  @discussion Its current job is word kerning, i.e. adjusting the width of spaces to match the set
+    wordKernedSpaceWidth. If word kerning is not needed, set the layoutManager's delegate to nil.
+ */
+@interface ASTextNodeWordKerner : NSObject <NSLayoutManagerDelegate>
+
+/**
+  The following @optional NSLayoutManagerDelegate methods are implemented:
+
+- (NSUInteger)layoutManager:(NSLayoutManager *)layoutManager shouldGenerateGlyphs:(const CGGlyph *)glyphs properties:(const NSGlyphProperty *)props characterIndexes:(const NSUInteger *)charIndexes font:(UIFont *)aFont forGlyphRange:(NSRange)glyphRange NS_AVAILABLE_IOS(7_0);
+
+- (NSControlCharacterAction)layoutManager:(NSLayoutManager *)layoutManager shouldUseAction:(NSControlCharacterAction)action forControlCharacterAtIndex:(NSUInteger)charIndex NS_AVAILABLE_IOS(7_0);
+
+- (CGRect)layoutManager:(NSLayoutManager *)layoutManager boundingBoxForControlGlyphAtIndex:(NSUInteger)glyphIndex forTextContainer:(NSTextContainer *)textContainer proposedLineFragment:(CGRect)proposedRect glyphPosition:(CGPoint)glyphPosition characterIndex:(NSUInteger)charIndex NS_AVAILABLE_IOS(7_0);
+ */
+
+@end
+
+NS_ASSUME_NONNULL_END