445 bug multilingual tests failing

This fixes the multilingual tests that are currently failing on master.

It seems that when the multilingual extension was written, package dicts never contained ints as values. Now they do. But postgres cannot compare an int to a string so it crashes. Converting the ints to strings before trying to look them up in postgres fixes it, although there may not be any point in looking up translations of ints (!), so maybe it should skip them instead.

What about other non-string types that might appear as values in package dicts? Currently it seems there aren't any, apart from the handful of types that the plugin already handles is explicitly, but maybe it should skip any other values that aren't `isinstance(basestring)`.