Expose string functions in all builds

These are useful beyond just debug and printing builds

Correct separation of printing and debug builds

Fixes some build issues with 541289a32603cee8242b5360b05e8f0c52795433
as well as further allowing debugging (via the capdl interface) to
happen when printing is turned off.

unsigned int -> word_t

Add ability to set a human readable thread name when running kernel in debug mode