dropping files to Kicad manager :
*.kicad_pro, *.pro -> open project;
gerber and job files -> open in Gerbview editor;
Eagle and Cadstar files -> open project.
dropping file to schematic editor -> append schematic;
dropping library file to Symbol editor -> add library;
dropping board file to PCB editor -> append board;
dropping library or footprint file to Footprint editor -> add library or import footprint;
dropping ZIP file or gerber files to Gerbview editor -> open files;
dropping sheet file to Drawing Sheet editor -> open sheet.
Fixes https://gitlab.com/kicad/code/kicad/-/issues/11638
Also makes sure the progress dialog is closed when we're done reading
symbols (it used to stay up for much of the symbol editor initialization).
Also makes sure that any cancel in the preLoad step is honoured in the
sync step. (The preload is done because it is multi-threaded and therefore
faster than the single-threaded sync.)
Also makes sure that individual threads pay attention to the cancellation,
not just the GUI thread.
Fixes https://gitlab.com/kicad/code/kicad/issues/8372
ADDED: Radio button controls to symbol library editor save as file dialog
to allow the user to choose the appropriate symbol library table changes
to be made after the library is saved.
Fixes https://gitlab.com/kicad/code/kicad/issues/4911
Prior to this change the "Save As.." command would take a different action
based on the state of the editor which could be confusing. There are now
separate commands for saving the currently selected library or symbol.
CHANGED: The implicit save as menu entry which would save the currently
selected library if no symbol was selected or the current symbol to a
different library. There are now separate save as commands for libraries
and symbols to make it obvious what is being saved.
1) Zero out selection in tree when canvas captures focus so that
save/save as actions will go to canvas, not tree item.
2) Make save do a save to schematic when the canvas symbol is from
the schematic.
3) Copy fields when doing a save to schematic (setting the lib part
doesn't update them on its own).
4) Remove no-longer-necessary calls to update schematic after
saving symbols (the schematic symbols are no longer hot-linked).
Fixes https://gitlab.com/kicad/code/kicad/issues/6763