Fixed a bug in the MenuListener

where, when ESCAPEing the implementation chooser, the MenuListener would
attempt to switch to the null fractal / color palette, with ill results.
Improve keyboard usability of HsbRotatePaletteEditDialog
Better start point of JuliaSet

If you start the Julia Set directly (instead of switching to it from the
Mandelbrot Set, it now has a slightly more interesting start point than
(0,0). TODO: Make configurable
Added a thread name to the DebuggingLog

"DebuggingLog". Of course.