WIP Node Platform - Add support for settable user variables

* Update Openshift mcollective agent and ddl
* Move gear ssh key creation to happen when gear created
* Added oo-user-var-add/remove/list commands
* Create .env/user_vars when creating gear

Bug 988759 - Failed to override the existing variables
Bug 988691 - Failed to add the 25th user variables
User vars node changes:
 - Use 'user-var-add' mcollective call for *add* and/or *push* user vars. This will reduce unnecessary additional code/complexity.
 - Add some more reserved var names: PATH, IFS, USER, SHELL, HOSTNAME, LOGNAME
 - Do not attempt rsync when .env/user_vars dir is empty
 - Misc bug fixes
Added User environment variables support in broker

Use x.present? instead of (not x.nil? and  not x.empty?)
Added REST api support for user environment variables

Allow environment variables support for REST version <= 1.5