Tighten up the filtering of actool.
Tighten up the filtering of actool.

While looking at some actool flake on Travis, noticed these things that
should help ensure nothing gets dropped that might be useful.

- Ensure sections have a name with 1+ character instead of 0+.
- Fix one regex to escape the periods in the version number for an explicit
  match instead of matching any character.
- If stdout gets any lines before the first section, always report them (this
  should catch anything happening before during startup of the tool).

PiperOrigin-RevId: 224560980

bazelbuild/rules_apple,bazelbuild/rules_apple,bazelbuild/rules_apple,bazelbuild/rules_apple