DDF-455 Add auto-complete to the application console commands.

This implements the logic identified at
https://tools.codice.org/jira/browse/DDF-455?focusedCommentId=11846&page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel#comment-11846
Merge pull request #3 from bradh/DDF-445

DDF-455 Add auto-complete to the application console commands.
Reviewed by: @shaundmorris and @mrmateo