#43 Combine keys for barcode object

[d-v-h]

I use two database fields for zip codes: the ZIp5 and
the ZIP4. When I print labels, I combine the two. I'd
like to be able to create barcode objects that can
combine data from two keys:

{7}{-8}
90210-1100

As a seperate issue, it would be nice to associate
certain text exclusively with a key, so it won't be
printed when the key is empty. In the example above,
the dash between the ZIP5 and ZIP4 would not be printed
if the ZIP4 key was empty.

Or in this example: if there's no middle initial, don't
print the period:

{1} {2.} {3}
First I. Last

An easy way to do this would be by including the
additional text within the curly brackets.