This code is closely tied with the hash server in bitbake and also means
we can't relibably test the hashserv runqueue functionality without OE
metadata. Moving this to bitbake as a MixIn class makes most sense
and encourages code collaboration and reuse as well as enabling easier
and more accurate testing of the APIs.
(Bitbake rev: 7bb79099a6c1b463d6ae9226c4cab5e76a965675)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>