Fix several bugs in the service data routines for verification

[cmickeyb]

Small changes to fix several problems with the way last_verified_time is handled in the service data store. Improves variable naming and ensures that the value of last_verified_time is pushed through.

[g2flyer]

Code looks good to me afaict -- i'm not very familiar with this code .... -- and test still works nicely

[cmickeyb]

Code looks good to me afaict -- i'm not very familiar with this code .... -- and test still works nicely

which really means that we need to do a better job of testing verification. pdo-shell does not make checking a specific numeric value easy. may need to add some support just to make writing tests like this easier.

[bvavala]

looks good