Update console to use new events system.

Summary: This updates the console to use the new events system, including hooking it up so that the `~` key works to toggle the console and so that keyboard events do not pass through to the rest of the game when being consumed via the console.

Test Plan: N/A, for code review only

Reviewers: Sabre070

Reviewed By: Sabre070

Differential Revision: http://code.redpointsoftware.com.au/D88