[Pkg-samba-maint] talloc packaging as an example of multi-pyversions package

[Michael Tokarev]

Hi.

I tried to experiment with building multiple-pyversion library out
of samba packages, using talloc as an example.  This is due to the
current python transition mess.

And the thing appears to be quite messy too, while it does not look
practically messy in d/rules (where all the magic happens).

I pushed it to a separate branch for now, multi-python, instead of
main.  But there's just single commit to implement in d/rules, and
a single commit to enable multiple versions in d/control.

Previous packaging changes makes these 2 last commits much easier,
doing all the preparation and cleanup work.

The ugly part is waf. I absolutely detest waf by now :)  It is ugly
because the whole thing is now built several times. Including the
configure step (which is about 100 times slower than build!).
Instead of just the python parts.  But this is how it is, there's
nothing can be done with it so far.

Unless we want to perform manual build of individual files directly
from d/rules. Which is, in fact, a good possibility too, but it will
only work for this simple library (where each object is built from
single source only). It wont work for other libs.

Samba definitely should grow an ability to build in a subdir, at the
very least, instead of requiring copying the source, - it is trivial
to implement, by passing "out" and "out_dir" properties for certain
objects in there.

Please take a look at the multi-python branch.  It was an interesting
experiment.

Obviously this can't be used for building samba :)

Did I mention waf is awful? :))

/mjt