Prefer static to extern in ebrowse

Prefer static to extern in ebrowse

* lib-src/ebrowse.c (info_where, info_cls, info_member)
(info_position, options, yyival, yytext, yytext_end, yyout)
(yyline, filename, is_ident, is_digit, is_white, f_append)
(f_verbose, f_very_verbose, f_structs, f_regexps)
(f_nested_classes, min_regexp, max_regexp, inbuffer, in)
(inbuffer_size, string_start, class_table, member_table)
(namespace_alias_table, global_symbols, current_namespace)
(all_namespaces, namespace_stack, namespace_stack_size)
(namespace_sp, tk, keyword_table, search_path)
(search_path_tail, scope_buffer, scope_buffer_size)
(scope_buffer_len): Now static.
(options): Now const.