Bug 996491: Show warning when using snapshot and near disk quota

When the gear user's disk usage is >= 90% of quota, display a warning when
snapshotting or restoring (as these operations can fail in unexpected ways
when disk writes fail).
Fix bug 999013: always remove unprocessed env/*.erb files from cartridge dir during compatible upgrade
Fix bug 999189: gear upgrade extension is a no-op if release version doesn't match supplied version
Merge pull request #3427 from ironcladlou/bz/996491

Merged by openshift-bot
Merge pull request #3440 from pmorie/bugs/999013

Merged by openshift-bot
Merge pull request #3449 from pmorie/bugs/999189

Merged by openshift-bot
Automatic commit of package [rubygem-openshift-origin-node] release [1.13.9-1].
Automatic commit of package [openshift-origin-broker-util] release [1.13.8-1].
Automatic commit of package [openshift-origin-cartridge-postgresql] release [0.6.5-1].
Automatic commit of package [openshift-origin-cartridge-php] release [0.8.6-1].
Automatic commit of package [openshift-origin-cartridge-python] release [0.8.6-1].
Automatic commit of package [rubygem-openshift-origin-controller] release [1.13.7-1].
Automatic commit of package [openshift-origin-cartridge-phpmyadmin] release [1.13.4-1].
Automatic commit of package [rubygem-openshift-origin-console] release [1.13.6-1].
Automatic commit of package [openshift-origin-cartridge-switchyard] release [0.6.3-1].
Automatic commit of package [openshift-origin-cartridge-jbosseap] release [2.7.5-1].
Automatic commit of package [openshift-origin-cartridge-jenkins-client] release [1.12.3-1].
Automatic commit of package [openshift-origin-msg-node-mcollective] release [1.13.8-1].
Automatic commit of package [openshift-origin-cartridge-jenkins] release [1.13.6-1].