Add interface to USGS CenCalVM.
Added missing file.
Fixed small bugs in USGS CenCalVM queries.

Switch to maxres queries. Decrease elev until Vs > 0. Fix trapping errors. Don't query below max depth of model. Use minVs.
Add output of USGS model label in log file.
Remove superfluous checks when closing database.
Merge branch 'baagaard/master-add-model-usgscencalvm'

* baagaard/master-add-model-usgscencalvm:
  Remove superfluous checks when closing database.
  Add output of USGS model label in log file.
  Fixed small bugs in USGS CenCalVM queries.
  Added missing file.
  Add interface to USGS CenCalVM.