Note that since the markup might exist for other reasons, it has
to be turned on with a preference setting. (It goes through a set
of bitflags so the same architecture can be used for other markup
structures that we might want to support in the future.)
Note also that this is more about engineering nomenclature than
visual formatting. In that respect it's more similar to overbar
than italic or bold.
Split antialiasing options out from display options. Move
antialiasing to common. Duplicate the rest of display options
for Eeschema.
Implement OnSelectGrid and hookup GAL canvas refresh to
SetPresetGrid.
Add Grid Settings... to View menu and move Show Grid from
preferences to View Menu to match Pcbnew.
Jeff Young