Re-raising exceptions in Tarmac hides the real exception

[Paul Hummer]

While trying to track down the cause of bug #617689 I found that we have a pattern that is actually hiding the real exception. It looks like this:

try:
    do_stuff()
except Exception, e:
    raise e

This means the traceback is wrong. What we should be doing is:

try:
    do_stuff()
except:
    raise