propagate translator exceptions (see for_pnorman branch)

Hello Paul,

I've been working on a translator and found that exceptions from my translator functions were not appearing.  I came up with a solution and would be grateful if you'd except it into the mainline.  I also fixed a failing test.  It seems that the sp_usinas test data attributes are in Latin-1 not UTF-8.  But if the test passes on your machine, maybe I'm wrong about this.

Ciao,
Brian