[Commands] Add #removeitem Command. (#1847)

- Add #removeitem [Item ID] [Amount] command to remove items by amount versus nuking them all, removes all if amount is greater than what you or your target have.

zone/CMakeLists.txt

@@ -469,6 +469,7 @@ SET(gm_commands
     gm_commands/reloadworld.cpp
     gm_commands/reloadworldrules.cpp
     gm_commands/reloadzps.cpp
+    gm_commands/removeitem.cpp
     gm_commands/repop.cpp
     gm_commands/resetaa.cpp
     gm_commands/resetaa_timer.cpp