* Remove unused IChatCommand.
* Lots of refactoring into a shared context.
* Removed ICommonSession from server concmd Execute.
* Added argStr parameter to concmd execute.
* The execute function of client concmds now returns void, use the new shell.RemoteExecuteCommand function to forward commands.
* Finally move shells and commands into shared.
* Console commands can now be registered directly without a class in a shared context.
* Engine API Changes.
* Repair rebase damage.
* Update Submodule.
