Avoiding compatibility errors with python 3

[LorenzoSacchi]

I know that yum will be deprecated, so no python 3 support is expected. The best thing to do would be to change all scripts from #!/usr/bin/python to #!/usr/bin/python2.7 This would give people freedom to choose default version of python without errors

[james-antill]

Even centos:5 has /usr/bin/python2 ... so I guess it's fine to change them to that at this point, when it's obvious /usr/bin/python is going to be one more casualty of py3, if you want to do a patch.

[j-mracek]

The problem is that there is no possibility how to release the patch.

[james-antill]

I assumed this was more for random people who wanted to use the code from git, or build their own packages. I'm fine with just rejecting everything if you want someone to fork it somewhere else, if they care enough ... but I figured this was easy enough to validate we could merge it without any real work.