[Tilesathome] Reworked request handing out somwhat (was: Queue issues)

[spaetz]

OK, I have done some ork to improve the situation. We will hand out requests now depending on the state of the upload queue.

Priority 1 requests are handed out if the uploa queue < 1500
Priority 2 requests are handed out if the uploa queue < 1200
Priority 3 requests are handed out if the uploa queue < 1000
Priority 4 requests are handed out if the uploa queue < 700

This should make sure that the server always has something to crunch and it should make sure that no high priority requests are get stuck in the upload-waiting loop.

It's a rather simple, but hopefully effective solution. If it works out, we could even remove the go-nogo script.

spaetz