Added capitalize and title functions for strings

Same comment as the other PR -- could we combine the two test files into a single test file?  Also it's nice to just print out the results of the test rather than asserting on the output -- the tester will take care of that for us.

Also, I know I haven't been very consistent about it, but I don't think we should put "_test" at the end of the test name.  They're already in the tests directory :)