Change signature of 'Automake::Options::_process_option_list()'.

Change signature of 'Automake::Options::_process_option_list()'.

This only modifies internal details in the automake implementation,
bearing no externally visible effect, but preparing the way for the
final fix of Automake bug#7669 a.k.a. PR/547.

* lib/Automake/Options.pm (_process_option_list): Now accepts as
arguments a list of hash references with keys 'option' and 'where',
where 'option' is an option as might occur in AUTOMAKE_OPTIONS or
M_INIT_AUTOMAKE, and 'where' is the location where that occurred.
(process_option_list, process_global_option_list): Update.
* automake.in (handle_options, scan_autoconf_traces): Update.