Nice to have option to add triggers with priority

[srikrishnacj]

Sundial has only methods to add trigger to a job. however it assumes default priority for every trigger. Adding a trigger with priority to job would be useful. It is very essential for my project.

My use case follows.
An object has 4 states active, running, waiting, expired.
Active and running state events may be fired at same time.
running state must follow after active state.
but with out trigger priority, it is possible that running state event gets fired before active state event.