strtoul() was accepting the characters immediately above ASCII 0..9 as
valid hex digits, due to a missing comparison.

Signed-off-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>

	Timer subsystem initialization code in core/timer.c

	Split the BIOS and RTDSC timer drivers from i386_timer.c

	Split arch/i386/firmware/pcbios/bios.c into the RTSDC
	timer driver and arch/i386/core/nap.c

	Split the headers properly:
		include/unistd.h - delay functions to be used by the
					gPXE core and drivers.

		include/gpxe/timer.h - the fimer subsystem interface
					to be used by the timer drivers
					and currticks() to be used by
					the code gPXE subsystems.

		include/latch.h	- removed
		include/timer.h - scheduled for removal. Some driver
					are using currticks, which is
					only for core subsystems.

Signed-off-by: Alexey Zaytsev <alexey.zaytsev@gmail.com>

This reverts commit ed06bd8a89.

Kill off use of etherboot.h outside drivers/net.

correct prototypes for srandom(), rand() and srand().

with octal yet, but we can probably live without that.

stack or INT 13 emulator etc.

automatically linked in on demand.

Corrected warnings in misc.c.  strtoul() really should be
  unsigned long strtoul ( const char *p, const char **endp, int base )
but such is not the ANSI standard.