Modifies prettyprint methods for compatibility.

These changes make it easier to compare the ast from
the master and the dupDecls branch.  Also corrects
map()before()after() on importNodes to map the annotations,
and nameString for identifiers, which must be a method.
Adds ‘do’ to BuiltInList.

This is from the dupDecls branch.   Also adds a gc
decl to the prelude_clone method.