Preventing notes from being beamed when using \breathe

Notes that are separated with a \breathe sign are usually not beamed in engraved music. However, LilyPond currently ignores it by default. Here is a way to define a new command that includes a \noBeam instruction. You can even name it breathe, if you want to replace the existing function; however, as the example shows, there are some limitations too, that require explicit manual beaming in some situations.