[Python] Fix to conversion of samples from Python 3 to Python 2

Some calls to the print function weren't being converted to print statements
correctly by 3to2, so now we use the alternative fix, which is to use the
backported print function.

Fixes Issue 216.

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@2952 02a645c2-efd0-11dd-984d-ab748d24aa7e
[VCS] Use local variable declarations where possible

git-svn-id: https://cantera.googlecode.com/svn/cantera/trunk@2953 02a645c2-efd0-11dd-984d-ab748d24aa7e