Some fixes to portfolio

Some fixes to portfolio

* respect output lang
* fix export variable for BOUND_VARIABLE
* support export of SUBRANGE_TYPE
* statistic for lastWinner, other minor stat changes
* fix running of multiple threads on checsat/query
* changes of Assert -> assert which became private
* fix some destruction time order issues
* fix Pickler with AssertionException going private

Fixed by not fixing:
* portfolio+datatypes does not work
  - added ExportUnsupportedException to more places, switches
    to sequential
   (still TODO / decide : not switch silently, but print error)
   > note: this exception now needs to be (and is) defined in expr.h

Known issues:
* problems in portfolio+quantifiers
   - at least some problems appear to be because of static variables
   (will be later "fixed" like the datatypes)

(this commit was certified error- and warning-free by the test-and-commit script.)