CPS transform the program before compiling

This means the primitives get access to the continuation, so e.g.,
call/cc can work.

My CPS transform is probably a bit gammy. It seems to do a bit too
much work in the case of left-left-lambda (I haven't put a special
case for that in).
A script to CPS-transform a program and display the result
Merge branch 'master' into cps

Conflicts:
	Makefile
	eval
Use pp for cps too
Add a call/cc for now

Needed a bit more care to avoid (or at least, to make less likely)
shadowing, which erlc doesn't like. Makes the intermediate forms a bit
easier to read by giving gensyms a prefix.
Change script name to differ from branch name
Merge branch 'master' into cps

Conflicts:
	Makefile
Two! Two primitives!
Merge branch 'cps'

Conflicts:
	compiler.erl
	primitives.erl