\bendOn turned into a music function with \noBreak (patch by Harm)

If a bending happened to be applied over a line break, the file did
not compile and \noBreak commands should be added as a workaround.
line breaks over bending notes are now disabled

suggest also using Voice and TabVoice
change status to buggy

The snippet is documented and mostly works, but there are still some
issues and needs more testing.