Several updates, mainly to the "heap objects" section.

updates

Added CAF text to rts document

Correct a couple of things: WHNF closures can be partial applications
as well as constructors.

Numerous small changes

	* update layout of info tables.
	* macros \Section, \Subsection etc. for making labels more
	  consistent.
	* macros \secref, \figref for consistent cross-references.
	* fix some cross references.
	* lots of other small changes.

A major rewrite/reorganisation.
New material on bytecodes.
Deleted some of the really out of date stuff about the old system
 (You might have to checkout the previous revision if you need
  historical info.)
I have not merged the sections on TSOs and Stacks.
 SimonM has a clearer idea of what the TSO status words look like and
 I think he said he'd written a new section with stacks part of TSOs.

Added an overview section, commented out some of the more bogus parts of the document (but some bits still remain)

couple of minor fixes

Added 'standard closures' to discussion of how Hugs enters an object

Improved glossary/terminology at start - added unpointed and unboxed.
Created a section at start to describe the source language.  At the moment,
 all it contains is a description of unboxed tuple constructors.
Replaced erroneous uses of "closure" with "heap object".  According to
 the glossary, closures are enterable - things like stack objects
 are not enterable so they can't be closures.
Clarified section 2.7 (heap and stack checks): why should we not move Hp
 during heap check?
Added comment that I don't believe in the notion of fixed headers.

Latest batch of changes.  Merge SRT and Tag fields in the info table,
now that there isn't a bytecode pointer there.

new pictures

latest round of changes.

today's changes.

outstanding changes

finished today's changes.

add RTS draft document

add RTS document into the tree