Tidyed up help printing code. Added unit tests for wacky (empty and large strings) command, parameter and option descriptions, closes #106. Corrected header guard in Print.hpp, closes #108. Separated debug and error messages (created separate callback for error messages), closes #107. Added malloc() NULL detection when registering option with command, closes #109. Removed text 'Debug' when running the unit tests as part of 'make', closes #110. Stopped Clide from printing tons of info to stdout when running unit tests, closes #111.