dev-perl/MCE: Bump to version 1.821.0

dev-perl/MCE: Bump to version 1.821.0

Upstream:
- Fix bug in MCE::Queue dequeueing from 0 items
- Optimised MCE::Core::Input::Sequence and Generator
- Remove signal handling for XCPU and XFSZ from MCE::Signal
- use posix_exit = 1 by default if Gearman is present at
  construction
- Recommend Sereal 3.015
- Add code block for progress reporting to MCE::Core
- Fix div-zero in MCE->yield
- Better worker scheduling when workers are slow
- mce_grep enhanced with regards to -r and missing path behaviour
- Add MCE::Queue::end
- mce_grep updated for determining chunk level.
- support z* grep in mce_grep
- Don't localise AUTOFLUSH
- Improved reliability inside eval
- Improved reliability under threads
- Optimised MCE::Queue::dequeue and MCE::Mutex::synchronie

Package-Manager: Portage-2.3.4, Repoman-2.3.2