[Muine] [UI CHANGES 5/6] Right click context menu for playlist (ML post from Iain)

[Peter Johanson <latexer gentoo org>]

[5/6] Right click context menu for playlist (ML post from Iain) - Proposes
adding a context menu for the playlist that plugins can add items to for
acting on given songs. I'm torn on this. The HIG specifically states
that you should try to avoid having items only available via a context
menu, but also suggests "...a popup menu for every object, selectable part,
and text input target..". If we do add this, it would make sense to add
items such as "Play", "Cut", "Copy", "Delete", and "Paste" to act upon
the selected song(s). Once Jorn's "information dialog" proposal is
implemented, an item for that would make sense here too. I'm hoping to
get the most feedback on this item, and the next one.

-- 
Peter Johanson
<latexer gentoo org>