dev-perl/Plack: Bump to version 1.4.300

dev-perl/Plack: Bump to version 1.4.300

- Use new examples logic

Upstream:
- Lint middlware now allows blessed coderefs as a PSGI app
- log4perl tests fixed for parallel execution
- Replace HTTP::Body with HTTP::Entity::Parser
- Increase buffer to 1MB for buffered requests
- Swap meaning of "%D" and "%T" in logs.
- Fix conditionalGET middleware for Last-Modified + ETag
- Handle cookie values with quotes correctly
- Stop upper-casing all heaer keys in ::Request->headers

Keywords:
- New deps, keywords dropped:
  alpha ia64 ppc ppc64 sparc

Package-Manager: Portage-2.3.4, Repoman-2.3.2