Add --identify-strict option. Handle ms-style implibs:

Add --identify-strict option.  Handle ms-style implibs:

        * dlltool.c (file scope): Added new globals identify_ms and
        identify_strict. New typedef dll_name_list_type, and globals
        identify_dll_name_list_head and identify_dll_name_list_tail. Added
        new global identify_member_contains_symname_result.
        (identify_append_dll_name_to_list): New function.
        (identify_count_dll_name_list): New function.
        (identify_print_dll_name_list): New function.
        (identify_free_dll_name_list): New function.
        (identify_search_archive): Changed signature to take function
        pointer to operation to apply to each member, and data to pass on
        to that function.
        (identify_search_member): Changed signature to accept user data
        from caller.
        (identify_member_contains_symname): New function.
        (identify_dll_for_implib): Rewrite. Now determines whether implib
        is ms- or binutils- style, before searching sections for
        dllname. Allows multiple dllnames.
        (identify_process_section_p): Search alternate section for dllname
        when implib is ms-style.
        (identify_search_section): Add additional conditions to excludes
        candidate sections from consideration.
        (usage): Added --identify-strict.
        (long_options): Added --identify-strict.
        (main): Handle --identify-strict option.
        * doc/binutils.texi: Document --identify-strict option.
        * NEWS: Document --identify and --identify-strict options.