Update copyright year
Fix crontab that use month of year and day of month

This patch fix the use of periodic tasks with
both month_of_year and day_of_month.

Before this patch, in July for a tasks that should
run in February, the periodic task run again and
again. Celery believes it is 5 months late when
it is 7 month in advance.
Backport of leak fix for #1129
Bubfixes for #1129
Tests passing
Use correct command in "celery control disable_events" example.
Fix crontab that use month of year and day of month

This patch fix the use of periodic tasks with
both month_of_year and day_of_month.

Before this patch, in July for a tasks that should
run in February, the periodic task run again and
again. Celery believes it is 5 months late when
it is 7 month in advance.
Fixing grammar in configuration options docs
Canvas guide example fix
Update ironmq.rst

Changed Rackspace DFW endpoint to ORD. (ORD is newest IronMQ installation for Rackspace; DFW is being deprecated.)
Fixes rst section
Avoid gc.collect
[worker] Now sleeps for 1 second if consumer restarted more than 5 times in 1 second.  Closes #1053
Updates Changelog
Now depends on billiard 2.7.3.32
Now depends on kombu 2.5.13
Bumps version to 3.0.22
flakes
tests passing
flakes