Add Display Settings to Footprint Browser.
Make each of them OpenGL on OSX and Cairo on other platforms.
Allow auto-zoom to be turned off and save last zoom setting.
Make ordering of tools in htoolbar consistent.
Standardize grid and zoom drop-downs.
Fixes: lp:1791667
* https://bugs.launchpad.net/kicad/+bug/1791667
There's no point in having both Save Symbol and Save Library when
only one can be selected at a time.
Also cleans up a bunch of extraneous icons, and fixes a few
copy/paste errors in menus and toolbars.
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.