Rename spec_helper to spec/helper
Add Coveralls for code coverage reporting
Add Coveralls badge [ci skip]
Prepare 0.4.3 release
We no longer use lock_exclusively!
Optimized lookup for Postgresql and MySQL. Falling back to read-ahead for others
Prepare 0.4.4 release
Merge remote-tracking branch 'upstream/0-4-stable'

Conflicts:
	delayed_job_active_record.gemspec
	lib/delayed/backend/active_record.rb