Bitmaps are now identified by an enum class instead of by pointers.
Bitmap loading and caching is now handled by a class in common, and
we no longer compile most bitmaps into the binary, so there is no
longer a bitmaps static library.
Instead, bitmaps are archived to a .tar.gz file which is installed
in ${KICAD_DATA}/resources/images.tar.gz
The source PNGs are checked in to Git as the original CPP files were,
so that people can build without the required dependencies to convert
SVGs to PNGs.
Initial support is also added for dark theme icons, although this
is not yet exposed in the GUI.
Stubs are present for multi-resolution image resources, but this is
not fully-baked yet and could use some refinement.
This allows for the tool framework to keep track of a universal
set of conditions for the UI state (enabled/checked/shown) for
controls of actions. It removes the need for the main menubar
menus to be CONDITIONAL_MENUs and be rebuilt on each open,
and instead makes the updates of the check and enabling of
items handled in the native wxWidgets way.
This commit switchs the 3d viewer and kicad project manager window
over to this system.