Add an AddrOf in Expression and stop using Place in the PrettyPrinter.
Remove some dead code.
Localize type signature prettyprinting to Declaration.
Factor out some common code.
Remove some unecessary code.
Add a list version of pvar and use that.
Remove remnants of Declaration placements in variable prettyprinting.
Remove the place datatype.
Merge pull request #75 from pjonsson/addrof

Add an AddrOf in Expression and retire the Place datatype.