Includes some dialog changes to go with the menu update.
Includes promoting the Pcbnew graphics mode back to main menu.
Includes renaming Graphics modes to Toolsets.
This is meant as a stopgap for 5.0, with plans to add proper scaled
icons in the 6.0 cycle. A function KiScaledBitmap() is added, which
works like KiBitmap() except it scales the bitmap according to the
calling window's font size. Controls have been added to all the main
applications to let the user select scaling manually (these were omitted
from smaller apps that didn't already have a place to put them).
In addition, in eeschema only, the pixel height of the system font is
shown in the options dialog for diagnostics. This is only for collecting
feedback before 5.0 release from users with different displays and will
be removed.
For a start, this contains the GAL display settings (AA settings and
grid styling).
In future, other modedit-specific settings could go here too.
Fixes: lp:1672150
* https://bugs.launchpad.net/kicad/+bug/1672150
SELECTION now holds EDA_ITEMs not BOARD_ITEMs so various places had to
change to casting the selected items to BOARD_ITEMs.
Fixed compilation warnings on clang (Tom)
When creating a copy of CONTEXT_MENU, always a CONTEXT_MENU instance was
constructed, whereas an inherited type should be used. Solved with
CONTEXT_MENU::create() that has to be overridden in inheriting classes.
Event & update handlers are now virtual functions, instead of setting
the handlers with Set{Event,Update}Handler().