Adds check for python2 binary; creates symlink to most recent Python 2.x installation if it doesn't exist
Adds user prompt to specify whether or not they want a Python 2.x symlink created for them at /usr/local/bin/python2
Merge pull request #961 from mdavid/check-for-python2-binary-during-autogen.sh-configuration-generation

Adds check for python2 binary; creates symlink to most recent Python 2.x...