fix for unification.k
add ==K for Bags
change to ==Bag
add better evaluation trace in case of stack overflow
add naive duplicate recognition to trace algorithm
remove Set, List, Map classes
fix copyright
Merge pull request #641 from dwightguth/stacktrace

add better evaluation trace in case of stack overflow
Fix and test for ArrayIndexOutOfBounds in UnparserFilterNew pretty mode
Updated ! with ?
Merge branch 'unified-builtins2' into issue-607
fix code review comments
fix tests
fix copyright
Merge pull request #638 from dwightguth/bags

add ==K for Bags
add getMinimalUpperBounds to Poset
fix code style
Merge pull request #648 from bmmoore/unified-builtins2

Fix and test for ArrayIndexOutOfBounds in UnparserFilterNew pretty mode
fix serialization bug
changed machine integers to be more amenable for symbolic computation