gEDA-dev: [pcb] lesstif toolbar

[DJ Delorie]

Some progress:

http://www.delorie.com/pcb/20080108-toolbar.png

I plan on adding png support (it only supports xpm so far) so I can
get blended transparency.  I'm also hoping to support different icons
for checked/unchecked/inactive states; at the moment I just draw a box
around the "checked" icons.

Toolbars can be added to any side, and stacked.  No magic to put in
the automatic layer control buttons yet though.

The icons are in the $share directory, so they can be used by the gtk
port also if we want to coordinate them.  Currently the gtk port
hardcodes them in its sources.

The pcb-menu chunk looks like this:

Toolbars = {
  top = {
    {@img:grid-none checked=gridsize,1                   SetValue(Grid,1)     fg=blue}
    {@img:grid-10   checked=gridsize,1000  SetUnits(mil) SetValue(Grid,1000)  fg=blue}
    {@img:grid-100  checked=gridsize,10000 SetUnits(mil) SetValue(Grid,10000) fg=blue}
    -
    {@img:toggle-silk ToggleView(Silk) checked=silk_shown}
    {Rats ToggleView(Rats) checked=rats_shown}
    {Pins ToggleView(Pins) checked=pins_shown}
    {Vias ToggleView(Vias) checked=vias_shown}
    {Mask ToggleView(Mask) checked=mask_shown}
    {Back ToggleView(BackSide) checked=back_shown}
    -
    {@img:toggle-silk SelectLayer(Silk) checked=silk_active}
    {Rats SelectLayer(Rats) checked=rats_active}
  }
}

In theory, the @img hook will work for menu buttons as well, but I
haven't tried it to see if it works.