[Tilesathome] Color reduction

[Jiri Klement]

Hi,

I've reduced number of colors in symbols from 24 to 8. Some symbols
looks a bit different now, but I think it's ok. Symbol are now normal
svg files saved in osmarender/symbols, so you can check them in your
favourite image viewer.

Next step is reducing number of colors used in stylesheets.
Unfortunatelly it's not possible to use only one css for all zoom
levels as pixel has different size on different zoom. But we can use
one css for shared attributes (fill, stroke, pattern...) shared by all
zoom levels and one css for each zoom containg zoom specific
attributes (stroke-width,...). Is this a good idea?

--
Jiri