1. I add makefile in ch02-ch07
2. I modify the file ch07/ex7_03.cpp ,because the include header
   is an error! It's ex7_02.h ,not ex7_2.h.
3. I modify the file ch06/ex6_51.cpp ,because in the source code ,
   the first line of main function is a show for error ,so
   I need note it to complete automation completation!
Merge pull request #110 from mudongliang/master

makefile in ch02-ch07