Cleaned up static analysis finds.

-Removed unnecessary instanceof check for HelpNode
-Removed unnecessary int casts.
-Removed code comparing String to JMenuItem
-Added type to Dropdown
-Removed extra semi colon.
-Changed mod check to be safe for odd numbers.(Note: mod is actually remainder and can return negative numbers.)
-Removed static qualifier from obvious instance fields and removed unnecessary lazy init of MapManager.(It is still lazy on class load.)