RF: move script running code into own module

Refactor code to run scripts into own module.  In fact I'm using a
version I refactored for another project, to make it easier to use
across projects, but I think this makes the code easier to read and
support.
BF: workaround missing __package__ in Python 3.2

Python 3.2 does not set __package__; work around for now.
RF: change "below" to "above" for higher directory

I tend to think of directories nearer root as being 'down', it looks
more common to think of this as being 'up', change according to Ariel's
suggestion.
Update Cython download URL
Merge pull request #437 from stefanv/travis-cython

Update Cython download URL
Merge pull request #418 from matthew-brett/use-scriptrunner

RF: move script running code into own module
Merge pull request #405 from gabknight/frozen_windows_executable_issue

fixed frozen windows executable issue
DOC - added a missing blank line