[OSM-dev] Support for multiple layers on the tiles at home server

[OJW]

Previously, uploaded images had filenames of the form tile_z_x_y.png.  That 
interface is still valid.

Now, uploaded images can also maplint_z_x_y.png, or cycle_z_x_y.png depending 
on what layer you want the tile to go into.  


Previously, tiles were viewed using URLs of the form 
http://dev.openstreetmap.org/~ojw/Tiles/tile.php/z/x/y.png.  That interface 
is still valid.

Now, tiles can also be viewed at 
http://dev.openstreetmap.org/~ojw/Tiles/maplint.php/z/x/y.png, and 
http://dev.openstreetmap.org/~ojw/Tiles/cycle.php/z/x/y.png.  These new 
layers are visible on the tile browser [1] and on informationfreeway [2]. 


This is just server API support, there isn't yet any content on the new layers 
although hopefully someone will modify the tiles at home client to generate 
cycle maps and debug maps to display there.


[1] http://dev.openstreetmap.org/~ojw/Browse/?x=1021&y=511&z=12&tileset=3
[2] 
http://www.informationfreeway.org/?lat=15027499.64681&lon=-10046575.07227&zoom=12&layers=000B
[3] http://wiki.openstreetmap.org/index.php/Tiles%40home/Layers