z80pack: clean up common devtty between versions
z80pack: share the lpr driver code
z80pack: add shared devlpr
zx128: multitasking support
zx128: fd_bankcmd eliminated at last
zx128: vt keyboard scan bug fixed
z80pack: update Makefiles to have correct rules for dev/../.. code
execve: per CPU magic, also allow for different program base

Use different magic numbers for different CPU types. Note that we need to
pass some kind of base info and check it in future (or support relocatable
binaries ?)

As noted by Atsidaev our handling of some of this was rather confused. We
now pass the size (top - PROGBASE) to the allocator. This sort of assumes for
6502 we'll set 0x0200 (or higher) entry and 0x0000 base and something similar
for 6809.

zx128 will still need a custom banking module eventually. Once someone
beats SDCC into banking the kernel code that can mostly live in 2 (or 3)
16K banks in an interface 2 cartridge with banking support then it can
use 0x8000-0xBFFF and lazy memcpy it from another page (or even exchange
two pages) on a taskswitch between two different 32K apps.

See: http://www.fruitcake.plus.com/Sinclair/Interface2/Cartridges/Interface2_RC_Custom.htm#SoftwarePaging
z80pack: kill dead code
zx128: custom banking added
Merge pull request #18 from atsidaev/clean-24112014

zx128 multitasking support
Merge branch 'master' of https://github.com/EtchedPixels/FUZIX

Conflicts:
	Kernel/platform-zx128/Makefile
	Kernel/platform-zx128/config.h
	Kernel/platform-zx128/crt0.s
	Kernel/platform-zx128/main.c
	Kernel/platform-zx128/zx128.s