[ issue1282 ] fixed incorrect handling of submodules in open public
[ issue1282 ] test case
Merge remote-tracking branch 'origin/maint-2.4.2'
[ fix ] added missing constructorForm in LHS.Unify
[ sharing ] resurrected pointer term representation

Type checking times are more or less the same,
slightly slower type checking (of std lib), but faster
serialisation.

Big win is actual call-by-need compile-time evaluation.
[ sharing ] updated error messages and interaction output

Things get more evaluated now, since evaluation gets shared.
[ sharing ] added more missing ignoreSharing
[ sharing ] updated error messages again
[ sharing ] enable forcing pointer equality for terms that compare equal
[ sharing ] debug printing of the entire signature