[Tilesathome] Tileset files

[Matthias Julius]

I have just committed an update to _unstable that lets the client
create Tileset files when CreateTilesetFile is set.  This is based on
the script kleptog has posted here a while ago.

Since the server doesn't know what to do with them the client won't
try to upload them.  And of course it will refuse to create them in
the automatic request modes.

To try it out:

  tilesGen.pl xy xxxx yyyy && tilesGen.pl upload

The tileset files will end up in uploadable and be named
Layer_Z_X_Y_UUID.tileset similar to zip files.

It would be good if someone could verify the validity of the created
files.



I would propose to amend the tileset file format a little bit.  Firstly
I think we should store the number of zoom levels in the header.  That
way we wouldn't need to store thousands of useless offsets for layers
with less than 6 zoom levels.

Secondly, we sould add a plain text (or XML or whatever) meta data
section after the end of the tile data (where the last offset points
to).  There we could store user id, client id, timestamp of when the
OSM data was downloaded and other more or less useful things.

These changes should keep the file format backwards compatible.

Matthias