Cairo supports antialiasing when rendering but can be slow when set to
sub-pixel mode. This bumps the minimum version of Cairo to 1.12
(available in 14.04 LTS as well as mingw) to support three antialias
settings (fast, good, best) that offer speed/appearance tradeoffs.
This can provide a higher-quality eeschema render as it works on a
per-element basis as opposed to the OpenGL per-screen antialias.
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.