install_with_python: Secure Python download with sha256 checks.

[Andrew Bartlett]

On Fri, 2015-06-26 at 10:48 +1200, Adrian Cochrane wrote:
> Thanks for spotting that missing "|| exit 1" I should've caught. 
> Here's 
> another go with your suggested refactorings.

Martin,

What do you think of this?  It isn't perfect, but it is an improvement
and so I would like to get this in.

Reviewed-by: Andrew Bartlett <abartlet at samba.org>

Thanks,

-- 
Andrew Bartlett
https://samba.org/~abartlet/
Authentication Developer, Samba Team         https://samba.org
Samba Development and Support, Catalyst IT   
https://catalyst.net.nz/services/samba