Add exterior condition lookup values to API

[timwis]

Currently the API returns a number between 0 and 7 for the exterior_condition property, and we use a lookup in the application to provide the string. Ideally the API would provide the string, like it does for zoning. Something like exterior_condition_description

The lookup values are hopefully in the database, but we use:

    // Exterior Conditions
    ,"ext_cond_0": "Not Applicable"
    ,"ext_cond_1": "Other"
    ,"ext_cond_2": "New / Rehabbed"
    ,"ext_cond_3": "Above Average"
    ,"ext_cond_4": "Average"
    ,"ext_cond_5": "Below Average"
    ,"ext_cond_6": "Vacant"
    ,"ext_cond_7": "Sealed / Structurally Compliant"

This is not a bug, just a wish list item. Not a big deal.

[CKiddDev]

This API enhancement will be planned and included as part of Iteration 2.