ELF objfmt size agnosticism:

ELF objfmt size agnosticism:
* Replace ulongs secthead.size, secthead.align, reloc.addr with intnums
* Calculate relocation size with intnums
* Create macros YASM_WRITE_32I_L, YASM_WRITE_64I_L to write 32/64bit
  intnums to buffer
This doesn't quite cover everything, particularly due to various calls
to yasm_intnum_get_uint for various bits of processing, but it's close!

Miscellany:
* Fix non-call to elf_reloc_delete()
* Remove unused secthead.addr, secthead_set_addr
* Create macro YASM_WRITE_64Z_L to write zero-extended 32bit value to
  64bits of buffer

svn path=/trunk/yasm/; revision=1030