Sanitize + simplify %patch "macro" parsing

Sanitize + simplify %patch "macro" parsing
- Use popt for parsing %patch options, give accurate error messages for
  invalid options instead of bogosity like "bad %patch arg: %build"
- Store all the variants we can get patch numbers into argv to avoid
  special cases when passing to doPatch(), this has the added bonus
  of removing the 1024 patches per line-limit (as if somebody cared)