Merge pull request #144 from mgage/master_IO_fix

Fix 'fileFromPath not defined or not exported'  error
updates to pccTables.pl
Fixing read_whole_problem_file bug

-  We fixed a couple of cyclic use calls in IO.pm
-  We moved not_null and pretty_print from PGcore into PGUtil and made
   a bunch of other changes to accomidate that
Fixed PGcore/not_null ref in AnswerHash
Changed fileFromPath back to standard importer stuff
Changed share to share_from with safe compartments.
revert unintended change
lots of upgrades to pccTables.pl, which is renamed to niceTables.pl, and pccTables.pl now redirects there
tidying things for develop branch
moved pccTables.pl to OPL/PCC/macros
Make COMMENTS from a given pg file accumulate and show them all,
(as opposed to only showing the last one).
Update compound problem macros to record which answers are used, so that the iscorrect and canshow options aren't needed.  Add PGML support.  Add documentation.
Fixed the name of the init function (was going to rename this scaffold.pl until I wrote my new versions that I think are even easier to use that these ones).
Merge pull request #152 from jwj61/develop

Make COMMENTS from a given pg file accumulate and show them all,

This is a small change.  I tested that in the library browser without this pull request only the last comment is shown and after all of the comments are shown.
Use WARN_MESSAGE macro instead of the old WARNING_MESSAGE and WARN
IMplementing MIkes fixes.
Further polish on pretty_print
Fix some documentation issues with contextComplexJ.pl
Merge pull request #156 from dpvc/patch-complexJ

Fix some documentation issues with contextComplexJ.pl

- Doc changes - Nothing to test.
Merge pull request #155 from cubranic/warn-message

Use WARN_MESSAGE macro instead of the old WARNING_MESSAGE and WARN

I check that each of the four error messages in PGGraders.pl works now.
Merge pull request #157 from Alex-Jordan/pccTables

Pcc tables

I tested all of the options described in the comment documentation in the macro file.  (Alex's test problem was helpful here.)  Everything seemed to work as advertised.
Merge pull request #154 from dpvc/patch-compoundProblem

Update compound problem macros