This also removes vector cover types which do nothing except obfuscate
the underlying implementation.
Mainly changes SCH_SHEET_PINS and CONFIG_PARAM_ARRAY (which will soon
be replaced by Jon's new stuff).
ADD: User can now decide to keep the hierarchy navigator open while working
on a schematic.
This behavior can be configured in eeschema->preferences->eeschema->Editing options.
ADDED: a config option to select (when clicking on a pin) the parent symbol
or only the pin.
Previously, when cliking on a pin, the parent symbol was selected.
Allowing the pin selection is mandatory in cross probing, and to display the pin
characteristics in some cases, for instance if a pin is flagged by the ERC tooL.
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.