Add Mapnik store
Use requests.

requests (using sessions):
$ time ./tc-copy --bounding-pyramid 4/0/0:0/12/12 tiles.openstreetmap_org null://

real 0m4.963s
user 0m0.324s
sys  0m0.056s

urllib2:
$ time ./tc-copy --bounding-pyramid 4/0/0:0/12/12 tiles.openstreetmap_org null://

real 0m9.012s
user 0m0.192s
sys  0m0.052s
Merge pull request #47 from fredj/requests

Use requests.
Handle request errors
Add more FIXMEs
Use a requirements.txt file for pip
Fix error filter on no tile
Fix rounding issue
Fix package creation
Alternate image import
Add MemcachedTileStore.

 # Usage example:
from tilecloud.layout.template import TemplateTileLayout
from tilecloud.store.memcached import MemcachedTileStore

keytemplate = 'mylayername/%(z)d/%(x)d/%(y)d'
memstore = MemcachedTileStore(['localhost:11211'], TemplateTileLayout(keytemplate))

 # As a caching proxy:
from tilecloud import TileStore
from tilecloud.store.findfirst import FindFirstTileStore

osmstore = TileStore.load('tiles.openstreetmap_org')
store = FindFirstTileStore([memstore, osmstore])

 # fixme: tiles from osmstore not saved into memstore
Merge pull request #48 from sbrunner/mapnik

Add Mapnik store with utfgrid support, and some fix
Merge pull request #49 from fredj/memcached

Add MemcachedTileStore.
Add notes about Mapnik and Memcached tile stores
Fix typos
Rename file for consistency
Remove stray execute permissions
Sort imports
Add TileCacheDiskLayout
Add TileCacheDiskTileStore