Added Lots of Documentation

Added some nice to haves
Improved and Unified General Code Layout

MathPad/MPDocument.h

@@ -8,11 +8,39 @@
 
 #import <MathKit/MathKit.h>
 
+
+
+/*!
+    @class      MPDocument
+    @abstract   This class is the document class that displays the MathPad user
+                interface.
+ */
 @interface MPDocument : NSDocument
 
+
+/*!
+    @property   expressionView
+    @abstract   The main expression view.
+ */
 @property (weak) IBOutlet MPExpressionView *expressionView;
+
+
+/*!
+    @property   resultLabel
+    @abstract   The label which displays the result of the calculation.
+ 
+    @discussion The label is placed inside the expression view.
+ */
 @property (weak) IBOutlet NSTextField *resultLabel;
 
+
+/*!
+    @method     evaluateExpression:
+    @abstract   Called by the expression view when it should be evaluated.
+ 
+    @param      sender
+                Typically the object that invoked the method.
+ */
 - (IBAction)evaluateExpression:(id)sender;
 
 @end