Refactored InfoSink. I have replaced most instances of sprintf with std::ostringstream to make it safer. I have made sure that everything still compiles and passes conformance tests.
Review URL: http://codereview.appspot.com/1391041

git-svn-id: https://angleproject.googlecode.com/svn/trunk@322 736b8ea6-26fd-11df-bfd4-992fa37f6226