Ideas:

return:	like iface, reccompile prec. 32, emit 'VM_RET'

function RET6
return (
	1+2+3
),

function ACCEPT (
	Sql(str = "insert into log..."),
	accept
),

function INTORSTR (
	int == 3 and (
		return "abc"
	),
	return 0
)

No typing at run time, so

1 + INTORSTR

should always emit the same (conversion) opcodes and the compiler must
therefore know about the type of INTORSTR in advance.

One option is to keep it simple, and make functions always return ordinals,
never strings; if a string return value is desired, that should be done using
'str' or another attribute.		-- this we settled for, EvB.

Another option is to make 'return' test if the function we're in (use extra
reccompile parameter) already has a type associated with it, and if not, set
that to the returned type; if one is set, make 'return' provide autoconversion
opcodes as expected.

It seems better to indeed store the type in the function entry, but set it
based on ret_ctx returned by the right hand side's reccompile. The problem with 
that is that 'return' doesn't know what type to emit.

I think the solution is to create two function definitions:

	function ACCEPT ...	- returns ordinal
	strfunc BLA ...		- returns string	(not implemented)



vm CALLFUNC:	contains immediate reference to code to call
		pushes ret IP to separate code stack


vm RETFUNC:	pops IP from code stack

