Update comments in Position.h.
Created configuration file for doxygen, and altered .gitignore so documentation
folder is ignored.
Minor edits:

-Changed .gitignore so gedit's backup files are ignore.
-Made a trivial edit to the comments in Position.h.
-Altered doxygen configuration so all .h files are scanned.
Fixed minor error is Square::setValue().
Fixed another minor error in Square::restrictValues().
Fully documented Square.h.
Created printing functions for the class Square.

Created Square::toString() and operator<<(std:::ostream, Square),
and commented them.