Dulwich C extensions and stand-alone Windows installation of bzr

[Martin Pool]

I hope we don't get into a "what is reasonable" debate, because there
are a lot of things about Windows development that are not reasonable,
and also not under our control.

I believe the technical facts are:

 * you can't use cygwin or mingw gcc to build extensions for a Python
built with msvc
 * all the python.org distributions are built with msvc (perhaps
because there are some limitations of w32 gcc; at any rate we hit some
in the past)
 * you need a close match between the Python interpreter and the
Python headers/etc used to build the dll

so

>  Normally, to make a DLL from them would be a 15-second job, even if I had to type the compilation/link command by hand.

might be true for DLLs in general, but as far as I know it's not true
for Python extensions.

Martin