Establish a naming convention for locals that are resources, components, systems, and actions

[phrohdoh]

My current thinking is:

• resource: *_rc
• component: *_comp
• system: *_sys
• action: *_act

Which means the following code:

        fetch_components!(arg, entities, [
            components(on_screen: OnScreenComponent),
            components(units: UnitComponent),
            mut components(decals: DecalComponent),
            mut components(selected_units: SelectedUnitComponent),
            mut components(transforms: TransformComponent),
            resource(keyboard_state: KeyboardKeyStates),
            resource(mouse_state: MouseState),
            resource(path_finder: PathFinder),
            resource(players: Players),
            resource(view_projector: ViewProjector),
            resource(viewport: Viewport),
            resource(occupied_tiles: OccupiedTiles),
            resource(terrain: Terrain),
            mut resource(action_batcher: ActionBatcher),
        ]);

Would be changed to:

        fetch_components!(arg, entities, [
            components(on_screen_comp: OnScreenComponent),
            components(units_comp: UnitComponent),
            mut components(decals_comp: DecalComponent),
            mut components(selected_units_comp: SelectedUnitComponent),
            mut components(transforms_comp: TransformComponent),
            resource(keyboard_state_rc: KeyboardKeyStates),
            resource(mouse_state_rc: MouseState),
            resource(path_finder_rc: PathFinder),
            resource(players_rc: Players),
            resource(view_projector_rc: ViewProjector),
            resource(viewport_rc: Viewport),
            resource(occupied_tiles_rc: OccupiedTiles),
            resource(terrain_rc: Terrain),
            mut resource(action_batcher_rc: ActionBatcher),
        ]);

Of course these suffixes (could be prefixes but in general I don't find that helpful, could be convinced otherwise) could be made more brief:

• resource: *_r
• component: *_c
• system: *_s
• action: *_a