* objdump.c (main) :Accept multiple -M switch.

* objdump.c (main) :Accept multiple -M switch.
* doc/binutils.texi: Document that multiple -M switches are accepted and that
  a single -M switch can contain comma separated options.
* arm-dis.c (parse_arm_disassembler_option): Do not expect option string to be
  NUL terminated.
  (parse_disassembler_options): Allow options to be space or comma separated.