Code review comment for lp:~jameinel/bzr/1.17-build-updates

I'd actually like to propose that this gets merged into bzr.1.17, however that doesn't seem to be mirrored yet on Launchpad.

Anyway, when going to build the win32 installers, I updated build_release.py and ran into some problems with make and generate_docs.py

Martin recently moved the file from . into ./tools, and then updated the Makefile to set PYTHONPATH so that it could still find bzrlib.

However, on Windows you have to do:
  PYTHONPATH=.;$$PYTHONPATH
versus
  PYTHONPATH=.:$$PYTHONPATH

(semicolon versus colon for those who have trouble distinguishing those 2 pixels.)

Anyway, generate_docs.py knows where it exists in the hierarchy, so rather than trying to work out how to write portable Make, I just went ahead and wrote portable python.

I need this on the 1.17 branch in order to build the installers, so it is somewhat time critical.