cron/cron_runjobs.sh Fix user-defined environment variables path

"rhc set-env" creates files in ~/.env/user_vars, but cron still looked for files in ~/.env/.uservars
Make the Python cartridge work with CentOS.
Bug 1028518
Merge pull request #4148 from jooert/patch-1

Merged by openshift-bot
Merge pull request #4150 from smerrill/feature/fix-cartridges-on-centos

Merged by openshift-bot
Merge pull request #4151 from danmcp/master

Merged by openshift-bot