fix bug : failed to reach end
	modified:   ch02/2.6/lexer.hpp
handle comments start with "\\"
	modified:   ch02/2.6/lexer.hpp
handle "\**\",ex 2.6.1 done
	modified:   ch02/2.6/lexer.hpp
	modified:   ch02/2.6/main.cpp
add operators < <= == != >= > for ex2.6.2
	modified:   ch02/2.6/lexer.hpp
ex2.6.2 done.
	modified:   ch02/2.6/lexer.hpp
	modified:   ch02/2.6/main.cpp
error when handling real
	modified:   ch02/2.6/lexer.hpp
fix bug : ommited - 48
	modified:   ch02/2.6/lexer.hpp
add handle_real()
	modified:   ch02/2.6/lexer.hpp
done, test codes and polish needed
commented
	new file:   makefile
Update README.md

added notes for section 2.6