Add compatability/support for pip 1.5 and fix erroneous rebuilds

Adds support for PIP 1.5 with older versions of python and setuputils/distribute by automatically detecting if wheels are supported and if they are not pass the --no-use-wheels flag.

Fixes erroneous rebuilds of virtualenvs as mentioned in
https://github.com/stankevich/puppet-python/issues/46

Fixes secondary method to determine pip version with facter.