Move constants module to shared directory.

Since constants.h is used all over, might as well make the module first.
Make maximum string length configurable.
Increase size of some strings likely to overflow.
Merge pull request #140 from QuLogic/short-strings

Fix too-short strings
Fix lists of auxiliaries objects.

Not adding files to the main variables means they don't get cleaned up.
Fix module list in auxiliaries directory.
Merge pull request #141 from QuLogic/fix-auxiliaries-clean

Fix auxiliaries cleaning