Adding new category "color_coded" for rendering of trails

For the purpose of rendering the color-coded trails using the tag "colour" or "color", when they are not used tags "osmc_symbol".

See also: https://groups.google.com/forum/#!topic/osmand/eLQiAMXYxu0
Merge pull request #68 from KKlim/patch-5

Add new category "color_coded" for rendering of trails