* Instantiated `GPJob` objects now have a `get_permissions()` and `set_permissions()` method
* Added `GPServer.system_message()` method for retrieving the system message
* Added `GPServer.login()` method for testing credentials or authentication status with the GP server
* Added configuration variable `GP_JOB_TAG` for overriding the tag applied to jobs launched through the Python client
* Fixed bug in `GPJob.get_child_jobs()` where child jobs would sometimes not populate in nested pipelines
* Fixed bug in `GPTaskParam.allow_multiple()` where parameters would erroneously report that they don't allow multiple values if `maxValues` isn't set in the module manifest
* Fixed bug in `GPTaskParam.is_optional()` where multi-value choice parameters would always report as required, regardless of required/optional status