Fixing read_whole_problem_file bug

-  We fixed a couple of cyclic use calls in IO.pm.  These were causing (for reasons mysterious and erudite) Translate.pm to be compiled and run before IO.pm was even compiled (this causes various functions in IO not to be shared into the safe environment)  
-  To accomplish this we moved not_null and pretty_print from PGcore into PGUtil and made
   a bunch of small changes to accomidate that.  

Test by viewing a bunch of different problems.  This will need to be tested on Ubuntu 14.04 (or another really new distro) because that was were the problem was occurring.  This is a hotfix and will eventually need a develop pull.