[Python-3000] Install python-3000 as python3

[Terry Reedy]

Guido van Rossum wrote:
> No, no, no!  *Eventually* Python 3.0 will just be "python". Until
> then, it needs to be "python3.0".

I think you should consider changing the installation policy to 
installing each file with its own pythonx.y name and alias exactly one, 
the system default, as 'python'.  Multiple installations are going to be 
common for several years, I suspect.

Currently on Windows, python3.0 is installed as just plain 'python'. 
This already causes problems when I want to choose 2.5 or 3.0.  In my 
quick start list, I have two entries which both say "Python (command 
line)" with the *same* icon.  Switching to admin, I just renamed one to 
Python2.5..., but that changes it also in the Python25 start menu 
directory, so I do not know if the change will survive the upgrade to 
2.5.3. Duplicate names are also a problem for the 
right-click-on-.py-file context menu.  It would be really helpful if 
there was a new icon for 3.0.

> Long agon, Red Hat installed Python 2 as "python2" instead of "python"
> and it led to endless problems.