Added Lots of Documentation

Added some nice to haves
Improved and Unified General Code Layout

MathKit/MPPowerFunction.m

@@ -10,15 +10,19 @@
 
 #import "MPExpression.h"
 
+
+
 @implementation MPPowerFunction
 
 MPFunctionAccessorImplementation(ExponentExpression, _exponentExpression)
 
+
 - (NSArray *)childrenAccessors
 {
     return @[@"exponentExpression"];
 }
 
+
 - (NSString *)description
 {
     return [NSString stringWithFormat:@"^%@", self.exponentExpression.description];