Release 3.0.0

• Use small pipe buffers for posix timers

• Move posix timer stuff into Coroutine

• Back to timerfd for linux as default

• Move CleanupPosixTimer to Coroutine destructor

• A few cleanups

What's Changed

• Incorporate Cruise LLC changes by @dallison in #20
• Add valgrind and abort functionality by @dallison in #23
• Add POSIX timer support for QNX and others by @dallison in #25

Full Changelog: 2.2.1...3.0.0