Add: 2.63 -- simulate arithmetic and logical shift
Add: 2.65 -- recursively compare parity.
Add: 2.66 -- return left-most one-bit.
Merge branch 'master' of github.com:Tomilla/CS-APP2e into solution
Merge: branch 'solution' Conflicts

Conflicts:
	Solution/Chapter 2/S2HP_2.63.c
Add: 2.67 -- solve backward compatibility(32bits).