gcc 4.6 warns on variables set but not used, so remove them.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Simple patch to make gcc happy during build in -Wall -Werror

Add .syslinux.derivative() and .syslinux.version().
Add an example script which shows how you can use .syslinux.derivative().

Signed-off-by: Gert Hulselmans <gerth@zytor.com>

Remove obsolete header used for old sleep function.

Signed-off-by: Gert Hulselmans <gerth@zytor.com>

For consistency with just about everything else, make syslinux.sleep()
count seconds, and syslinux.msleep() count milliseconds.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Add proper sleep() and msleep() functions, which among other things
call syslinux_idle(), and make Lua use them.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Merge Marcel Ritter's work on the lua branch:

The last time he wrote about the state of his lua branch:
http://syslinux.zytor.com/archives/2009-October/013383.html

The current state is:

- VESA:
  - switching to vesa mode works
  - loading/displaying images works
  - display text works (s. com32/lua/test/vesa.lua)

- PCI:
  - list PC devices + ID
  - get human-readable device name for device
   (s. com32/lua/test/pci.lua)

- DMI:
  - get DMI info (BIOS, Hardware, etc).
  (s. com32/lua/test/dmi.lua)

- syslinux:
  - loading files, kernel, initrd
  - start kernel, initrd, local boot
  ... just working on this, so no example lua file right now

Most of the actual merging work was done by Gert Hulselmans <gerth@zytor.com>.

Resolved Conflicts:
	com32/lib/sys/vesa/initvesa.c
	com32/lua/src/Makefile

Signed-off-by: H. Peter Anvin <hpa@zytor.com>

Need header files for functions we invoke.

Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>