[racket] compiling Racket to android and ios apps

I'm sure that defining "idiomatic" Racket would be a lively discussion, 
but, for purposes of the original discussion, I'll just weaken my 
original assertion:

* A good Racket programmer can, acting selflessly, without regard to 
his/her personal comfort, draw upon some of his/her Racket experience to 
help get up to speed in R5RS quickly.

Neil V.