* Fix casts in scheme evaluator
We really need test cases for all the primitives before we can use this
evaluator properly. Also test cases that run inside an environment,
which are a bit harder to construct.
* Add the cast fixes to racket support code
* More racket compile time evaluation fixes
We had the chez version of some primtives in the ct-support file. We
need a full set of tests for the primitives here too...
