fix Issue 13315 - std.getopt: implicit help option doesn't work without config.passThrough
fix Issue 13316 - std.getopt: implicit help option breaks the next argument
fix Issue 13317 - std.getopt: endOfOptions broken when it doesn't look like an option
whoops, forgot one ++i
Merge pull request #2433 from NilsBossung/13315

fix issues 13315, 13316, 13317 - std.getopt woes