minor cleanup
provide a simpler, better solution for wrapping
Restore some of the older code, python needs it
Convert c++ exceptions into scheme exceptions
Work around a Python bug.

WTF. Why am I working around python bugs in scheme code?
Unit test for catching exceptions
Fix the order of the exception arguments
Filter for teh correct exception type
Merge pull request #1160 from linas/thr

Convert C++ exceptions into scheme exceptions
Minor type fixes in comments
More typos
Merge branch 'master' into dev