*: add "noexcept" to many, many function prototypes

This eliminates some overhead, because the compiler doesn't need to
consider these functions throwing.

src/player/Control.cxx

@@ -151,7 +151,7 @@ PlayerControl::LockSetBorderPause(bool _border_pause)
 }
 
 player_status
-PlayerControl::LockGetStatus()
+PlayerControl::LockGetStatus() noexcept
 {
 	player_status status;