Renamed NSIndexPath+MPRemoveFirstIndex Category to NSIndexPath+MPReverseIndexPath

Added MPDisplayExtension Category to MPExpression and MPFunction
Added Methods to Invalidate the Cache to MPExpressionLayout and MPFunctionLayout

MathPad/NSIndexPath+MPReverseIndexPath.h

@@ -0,0 +1,23 @@
+//
+//  NSIndexPath+MPRemoveFirstIndex.h
+//  MathPad
+//
+//  Created by Kim Wittenburg on 23.04.14.
+//  Copyright (c) 2014 Kim Wittenburg. All rights reserved.
+//
+
+#import <Foundation/Foundation.h>
+
+@interface NSIndexPath (MPReverseIndexPath)
+
+/*!
+ @method indexPathByRemovingFirstIndex
+ @brief Provides an index path with the indexes in the receiving index path, excluding the first one.
+ @discussion Returns an empty NSIndexPath instance if the receiving index path’s length is 1 or less.
+ @return New index path with the receiving index path’s indexes, excluding the first one.
+ */
+- (NSIndexPath *)indexPathByRemovingFirstIndex;
+
+- (NSIndexPath *)indexPathByPrecedingIndex:(NSUInteger)index;
+
+@end