ADD zip4 and address_alphanumeric as an attribute

[robe]

This is Leo's request. He got mad that pagc_normalize_address strips his zip4 cause zip is only 5 digits and there is no slot for zip4.

Also since address is numeric (since it's used for range matching), non-numeric or weird numerics like 102 ½ st or 102R have or 102-103 have the second part stripped. The new field will allow the full address to be put in even if it has non-numeric bits.

Neither the new zip4 nor the address_alphanumeric will be used for geocoding, but will be used by pprint_addy if they are present for maintaining the integrity of the original address.