Add (basic) menu entry for customizing controls
Reorder menu event processing

Send events to Entries *before* Menus. Makes ControlEntries work better
Fix problems with opening menu/not setting control
Don't allow multiple binds for a single command
Make menu text smaller
Fix box position for ControlEntry
Fix key modifiers for ControlEntries
Add option for commands that cannot be rebound
Handle Unknown keys in key2str