Broken Panels

I have found the cause of a rather serious bug in Plane-Maker: sometimes instruments disappear from the hierarchy (but are still visible in the main window).

The problem is that the cut-paste facility, when used with multiple-instrument selections, was corrupting the hierarchy information.  Because of the way instrument hierarchies are managed, this corruption persists - even if it isn't visible.  So if you manage to ungroup everything, it looks okay until you work more, then the instruments disappear again!

This is a really bad bug of mine, particularly since a panel is such a time investment.  Here is what we'll be able to do in 930 to get around this:

1. A new "flatten panel" command simply ungroups everything and completely cleans the hierarchy.  All corruption of hierarchy is fixed with this command, finally exposing every instrument.  From that point on, you can then re-group and things should be okay.
2. I am fixing the cut-paste commands to not trash the hierarchy, and I am looking for any more hierarchy-corruption problems.
3. 930 has export/import of instrument groups to text files.  So another way around instrument corruption problems would be to export the panel to a text file, fix the grouping problems (which is a matter of moving the GROUP/END_GROUP lines) and then re-importing.  If you do not have a selection, the entire panel is exported, including any hidden items in the hierarchy.

I believe that text-based panel import/export will also be useful for sharing individual instruments (or clusters of grouped generic instruments), archiving work, and making large-scale changes using search-and-replace.