Merge pull request #1 from chessmasterhong/master

PHP solutions for problems 1 and 2.
Added python solution to problem 1
Added python solution to problem 2
Added python solution to problem 5
Added python solution to problem 6
Added python solution to problem 20
Added python solution to problem 22
Merge pull request #2 from mk200789/master

python solutions for problem 1, 2, and 5
Adding problem 2 in haskell
Adding problem 4 in Haskell
Adding problem 6 (Haskell)
Adding problem 15 (Haskell)
Revised problem 1.
Revised problem 1 and 2.
Added PHP solution to problem 6. Revised problem 1.
Revised problem 6.
Added solution to problem 20.
Added solution to problem 22.
Revised problem 22.
Added solution to problem 13.