by telling it that it is a macro that should be ignored

joinRuntime+teardownRuntime->Py_Finalize
remove the individual teardownFoo(), which had all become empty anyway.

modified git_svn_gotorev.py to work with both py2 and py3

Move the sqlalchemy 0.5 test to extra/

Use configurable path to cpython

This removes it from the debug testing configuration and should hopefully
reduce CI timeouts.

Improve comments, rename CLFunction

and a couple of the other related functions:
- addRTFunction is now an overload of FunctionMetadata::addVersion
- boxFunctionMetadata is now createFunctionFromMetadata (it doesn't return a box)
- createRTFunction was just a wrapper around new FunctionMetadata(), so get rid of it
- boxRTFunction is now FunctionMetadata::create

"CLFunction" never really made sense as a name, and some of the other related functions
didn't make sense either (especially after a couple refactorings happened).  Hopefully
this makes it less confusing.