[m-dev.] Changes to runtime.

[Tyson Richard DOWD]

> 
> Aaarrrgghhh! The result of merging the parallelism changes I made
> early this year resulted in unreadable gibberish. Oh no, not again!
> 
> I'm making some significant modifications to the runtime at the
> moment. In a few days I hope to have most of the changes made -
> most of them will have no effect on normal code (only code for
> which MR_REENTRANT or MR_PARALLEL are defined), so it will probably
> be okay to commit them before all the stuff for parallelism is complete.

Ok, commit this code first, then I'll reorganize things.

-- 
       Tyson Dowd           #          Another great idea from the 
                            #            people who brought you
      trd at .cs.mu.oz.au      #               Beer Milkshakes!
http://www.cs.mu.oz.au/~trd #	         Confidence --- Red Dwarf