Support for additional AllocationTimeUnits

[joeshannon]

We have a requirement to use a facility specific time unit for call allocation time. In DLS's case this is the "shift" equal to 8 hours.

Units may be added relatively easily e.g. #580 however for non-standard units this might not be an acceptable solution.

What might be a good approach to make this configurable, without adding the unit to all facilities?

One idea is to allow the set of units to be configurable in the application? This would require a UI to specify unit name and formula for conversion to seconds.

There is the concept of units already in the application but this may be orthogonal as is intended for the questions?

Thanks in advance for any suggestions/discussion.