This commit introduces 3 queues for sidekiq
"critical" for urgent jobs (weighted at 4x weight)
"default" for standard jobs(weighted at 2x weight)
"low" for less important jobs
"critical jobs"
Reset Password emails has been seperated to its own job
Heartbeat which is required to keep sidekiq running
Test email which needs to return real quick
"low priority jobs"
Notify mailing list
Pull hotlinked images
Update gravatar
"default"
All the rest
Note: for people running sidekiq from command line use
bin/sidekiq -q critical,4 -q default,2 -q low
After fork SiteSettings was not getting a new process id,
causing site settings not to refresh properly in unicorn
This code also centralizes the logic
