Problem #11
Problem #12
Fixed extraneous argument in Makefile
Merge branch 'problem011.cpp' into 011-020
Problem #13
Corrected Makefile
Merged #13 and correction to #12
Problem #14
Problem #15
Problem #16
Refactoring, up to number seven.
Adding some missing files
Updated #8
Updated #9
Updated #10
Updated #11
Updated #12
Updated #13
Updated #14
Updated #15