Update README
Link to 0.54.3 release notes
Add link to install from source instructions for jobcontrol
Add description of 0.54 feature flag
We really have more than one feature flag now
Update preferred feature flag activation syntax
Add release notes for 0.55.0
Add description for 0.55 feature flag
Add news entry for 0.55.0
Merge remote-tracking branch 'upstream/master' into chinese