Minor tweaks to comments.

change interface to add_persistent_funs (#73) and fix more calls

The new interface takes a list of strings naming theorems.
(The old interface took a list of (string * thm) pairs.)
The new way better ensures consistency of theory development and theory
load behaviour: you can no longer pass a name with a theorem that isn't
actually saved under it.

Theorems are looked up with DB.theorem, or failing that, DB.definition
or DB.axiom.

Alas, I found more examples using add_persistent_funs to add theorems in
ancestor theories. Rather than modify the ancestor theories, I have
opted to make the offending theories save the theorems they want to add
to computeLib themselves so they have a name in the current theory to
pass to add_persistent_funs.

If this behavior was appropriate for patricia too (da47401) change it.
Alternatively, if the ancestor theories should have exported those
things for computeLib anyway, search this commit for new instances of
"save_thm" to see what needs fixing.

Minor fixes.

Adopt ML-style syntax for case expressions and use freed up "||" for bitwise-or. See issue #24.

Correct spelling. Also move location of SInt and UInt.

Update that adds support for ThumbEE.

/* From the ARM reference...

ThumbEE

Is a variant of the Thumb instruction set that is designed as a target for
dynamically generated code. It is:
* a required extension to the ARMv7-A profile
* an optional extension to the ARMv7-R profile. */

Added support for hardware interrupts: reset, fiq and irq. This adds an extra
argument to the next state functions, i.e. we now have

arm_next : iiid -> HWInterrupt -> unit M

and

ARM_NEXT : HWInterrupt -> arm_state -> arm_state option

In the absence of an interrupt, the previous behaviour is obtained with

ARM_NEXT NoInterrupt : arm_state -> arm_state option

The single-step behaviour for interrupts can be obtained with

armLib.arm_step "" "reset" (* ARM_NEXT HW_Reset *)
armLib.arm_step "" "irq" (* ARM_NEXT HW_Irq *)
armLib.arm_step "" "fiq" (* ARM_NEXT HW_Fiq *)

There has also been some minor tidying-up to the code.

A few changes:

1. Make it clear that the ARMv7-M profile is not properly supported (yet).
2. Fix for EmitML script (following changes to memory).
3. Fixed parsing/encoding for 16-bit Thumb MOV (register) instruction.
4. Fixed bugs in model for BFI, SSAT and SSAT16.

Changes to the memory, to conform with the approach that Magnus explored in
ARM/experimental.

The memory now has type :address -> word8, instead of :address -> word8 option.
Accesses are recorded in a component state.accesses : memory_access list.

Fix bug in the model (relating to encoding of Thumb2 immediate values).

Also add more checks to encoding function and fixed a couple of bugs in
the parser/encoder/disassembler.

A new Monadic ARM instruction set specification. Covers all current ISA
versions i.e. ARMv4 to ARMv7.

Doesn't cover the ThumbEE, VFP and Advanced SIMD extensions. Also doesn't
model hardware interrupts - these will be added at a later date.

To use the armLib tools, Moscow ML users will likely have to apply the patch to
avoid the Chr exception.
<http://hol.sourceforge.net/mosml-chr-instructions.html>