fix issue294: re-allow cross-section substitution for setenv setting. 

deprecate indexserver options 

fix setenv/substitution bug 

doc ignore_outcome and bump doc version 

some fixes for detox, preparing 2.1.1 

prepare 2.1.0 release 

fix pep8 issue 

fix wheel packaging to properly require argparse on py26. 

also pass PIP_INDEX_URL because it's likely that the user wants to use it with the pip commands that run inside the tox run.

- backout ability that --force-deps substitutes name/versions in requirement files due to various issues. - This fixes issue228, fixes issue230, fixes issue231 which popped up with 1.9.1. - bump to 1.9.2 version