[Tilesathome] Request Priorities now sent to the client

[spaetz]

Minor server changes:

1) The server sends the request priority to clients now. The idea was that the client can then decide whether to fetch from the live API (interactive PRIO 1 requests) or from one of the read-only mirrors (changed tiles requests and bulk requests).

2) The server knows about Trondheim clients now and accepts them.

3) I have started work to deal with uploaded tileset files directly on upload, which would eliminate the extra upload processor and the upload queue. Not functional yet. Matthias, should the server deduce the x and y values from the tilesetfile metadata, or will these values be delivered as HTTP POST vars?

spaetz