Merge branch 'SIMPLEITK-540_DontAlwaysUseEZSetup' into release

* SIMPLEITK-540_DontAlwaysUseEZSetup:
  BUG: Adding missing cmake error variable for wheel process
  When installing the wheel package use ez_setup
  Add setupegg.py which uses ez_setup to get setuptools
  Do a try import on setuptools then fall back to distutils

Change-Id: I7f4981e769a399df0ef75d484e29b740b8bf7998
Merge branch 'release'

Change-Id: Ic1a93bb91bf24810ac137de1073688a94673b75f