This patch allows alarms to have time constraints specified.
If one or more time constraints are specified, the alarm is
evaluated only if the current time is within at least one
time constraint.
A field 'time_constraints' is added to the alarm model
that holds a list of the time constraints. Each time constraint
has the fields
- name the name of the constraint
- description description, default is auto-generated from start and duration
- start starting point(s) of the constraint, in cron format
- duration duration of the constraint, in seconds
- timezone optional timezone information
Change-Id: I2d1bcd6728affc31834d7e2f3a0bdd570b2413bb
Blueprint: time-constrained-alarms