Added write_highscore() function, and called it in main()

git-svn-id: svn+ssh://svn.pricetx.org/home/svn/numberguesser@55 d9013ba4-f9c6-e311-acb0-001cc0fd6b5d
Fixed typos and casted time_spent to an int

git-svn-id: svn+ssh://svn.pricetx.org/home/svn/numberguesser@56 d9013ba4-f9c6-e311-acb0-001cc0fd6b5d
Change write_highscore() to a void type

git-svn-id: svn+ssh://svn.pricetx.org/home/svn/numberguesser@57 d9013ba4-f9c6-e311-acb0-001cc0fd6b5d