Add sizeToContents in ChannelGUI and FeatureGUI, called when widget is
rolled, so we can remove resizing code from all of the individual
channels and features.
In RollupContents, use minimumSizeHint for calculated size, so that
minimumWidth can come from .ui file.
In DeviceGUI::sizeToContents(), call adjustSize(), so Device GUIs start
out at minimum needed size (which should restore appearance prior to
last patch).
In stackSubWindows, use available space for channels if no
spectrum/features present.
In stackSubWindows, fix spectrum from being sized too big, resulting in
scroll bars appearing.
Reset user-defined channel width in stackSubWindows, when channels are
removed.
Don't stack maximized windows.
There's one hack in Channel/FeatureGUI::maximizeWindow(). It seems that
when maximimzing a window, QOpenGLWidgets aren't always paint properly
immediately afterwards, so the code forces an additional update. I can't
see why the first call to paintGL doesn't work.
Plot Sun and Moon on sky temperature chart.
Plot markers on Galactic line-of-sight chart.
Create animations from Galactic line-of-sight chart.
Allow weather at antenna location to be downloaded from openweathermap.org
Allow target to be entered as Galactic longitude / latitude.
Add azimuth and elevation offsets to support scans around targets.
Add S7, S8 and S9 targets.
Refactor some code from GUI to main plugin, so computed values can be used in other plugins.
