Updated the Escort class

- Registering each excort at the client internally.
- Each escort known at the client can exchange targets.
- Each escort can acquire attack assistance from other escorts known at
the client.
- Made the MENU class more slick. Now menus are removed recursively for
CLIENTS.
- Added a few more types and fine tuned the documentation.

Dcs/DCSCommand.lua

@@ -0,0 +1,10 @@
+--- @module DCSCommand
+
+
+--- @type Command
+-- @field #string id
+-- @field #Command.params params
+
+--- @type Command.params
+
+env.info( "Command defined" )