rather than a time range. This makes more sense now that we
display every point on an automation line, rather than just
a subset. Makes the code a fair bit simpler, and should fix
some unexpected behaviours, especially when cutting automation
points.
git-svn-id: svn://localhost/ardour2/branches/3.0@12054 d708f5d6-7413-0410-9779-e7cbd77b26cf