#34 Vamp output display style hints

[Craig Stuart Sapp]

It would be nice if vamp output functions could be
given style hints which the host application could
apply to the data display (or it could ignore the
style hints).

For example in a hypothetical plugin, different
outputs have different meanings, and it would be
useful to colour or make a unique line style for
each output by default.

Currently in SV, the output display functions
all have the same style: Green with points connected
with lines. When I generate data from plugins
with multiple outputs, I must always go to the
control panel for that output layer and select
the "Colour" and "Plot Type" to keep track of
what data is what.

If my plugin could recommend to SV that it wants
the output function data to be displayed in
"blue" colour and "curve" plot type, then it would
save a lot of clicking and confusing on what
data is what.

Also, would be nice if the time instants could
generate style hints as well.