* bfd.h: change the documentation format.

	* bfd.h: change the documentation format.

	* created coff, elf and opcode and aout directories. Moved:

	aout64.h	==> aout/aout64.h
	ar.h		==> aout/ar.h
	a.out.encap.h	==> aout/encap.h
	a.out.host.h	==> aout/host.h
	a.out.hp.h	==> aout/hp.h
	a.out.sun4.h	==> aout/sun4.h
	ranlib.h	==> aout/ranlib.h
	reloc.h		==> aout/reloc.h
	stab.def	==> aout/stab.def
	stab.gnu.h	==> aout/stab_gnu.h

	coff-a29k.h	==> coff/a29k.h
	coff-h8300.h	==> coff/h8300.h
	coff-i386.h	==> coff/i386.h
	coff-i960.h	==> coff/i960.h
	internalcoff.h	==> coff/internal.h
	coff-m68k.h	==> coff/m68k.h
	coff-m88k.h	==> coff/m88k.h
	coff-mips.h	==> coff/mips.h
	coff-rs6000.h	==> coff/rs6000.h

	elf-common.h	==> elf/common.h
	dwarf.h		==> elf/dwarf.h
	elf-external.h	==> elf/external.h
	elf-internal.h  ==> elf/internal.h

	a29k-opcode.h	==> opcode/a29k.h
	arm-opcode.h	==> opcode/arm.h
	h8300-opcode.h	==> opcode/h8300.h
	i386-opcode.h	==> opcode/i386.h
	i860-opcode.h	==> opcode/i860.h
	i960-opcode.h	==> opcode/i960.h
	m68k-opcode.h	==> opcode/m68k.h
	m88k-opcode.h	==> opcode/m88k.h
	mips-opcode.h	==> opcode/mips.h
	np1-opcode.h	==> opcode/np1.h
	ns32k-opcode.h	==> opcode/ns32k.h
	pn-opcode.h	==> opcode/pn.h
	pyr-opcode.h	==> opcode/pyr.h
	sparc-opcode.h	==> opcode/sparc.h
	tahoe-opcode.h	==> opcode/tahoe.h
	vax-opcode.h	==> opcode/vax.h