Make cron.rm_job factor in temporal values.

This fixes #4765 by removing the job if no temporal values are passed,
and only removing the job if the passed temporal values match the
existing job, if they were passed.

Also, this commit changes the internal references to the temporal fields
to match the names of the fields in the cron.absent and cron.present
states, for consistency.
Merge pull request #5545 from terminalmage/issue4765

Make cron.rm_job factor in temporal values.