Minor fixes to pacify the warning machine.
Add assignment and binding rules.
Fix unnecessary reification issue with a separate reify rule for sequencing.
Remove dead code from previous attempts at reification.
Add show instance to CPPGenS.
Add some missing cType and cDecl cases.
Add declaration cases and program transformer.

The program transformer is a wrapper around declaration, to stitch together the
various forward declarations, and add the definition of the atInit trigger.