Make it so Pyflame can be built simultaneously against Python2 & Python3 about pyflame

[ogrisel]

I would be great if the configure script could introspect the python command found in the PATH to find out which version of Python to build against. This would make it possible to build a pyflame that matches the python versions in the currently enabled virtualenv.

On a related note, it should be possible to build manylinux1 binary packages for pyflames for common versions of Python and upload those packages to PyPI to make it trivial to install pyflame with pip (in a virtualenv or not):

https://github.com/pypa/manylinux

[eklitzke]

That is a pretty good idea, and definitely easier than what I was thinking. When I get a chance to work on this I'll start as a first step.

[eklitzke]

I have a POC of this in the deephack branch, which implements this by abusing C pre-processor macros. It can build an executable capable of profiling both py2 and py3 processes.

Things to do before I submit a real PR:

• redo all of the code that figures out what version of python the target executable is (major task)
• remove a few hard-coded things