bend: add snippet information
bend: remove old, unused code

Apparently there were 3 attempts to get the pointed-slur function
right, and the last one was chosen.  Previous attempts seem to be
unused.
bend: some cleanup
bend: override slur in appropriate place
bend: change variable names, remove spurious comments
bend: don't list Thomas as author (according to his wish)
bend: prevent grace notes from being erroneously beamed

The beaming problem appeared in version 2.17.28,
when automatic grace note beaming was added.
bend: change define-public to define

define-public seems to make no sense here.
bend: add description