Make "Expires" header RFC 1123 compliant
Make "Expires" header RFC 1123 compliant

The Expires header is missing a comma after the day, which makes it non-compliant with RFC 1123, and thus prevents caching by some proxies and CDNs.
Billups/TileStache,jbants/TileStache,TileStache/TileStache,Billups/TileStache,jbants/TileStache,TileStache/TileStache,MetGIS/TileStache,MetGIS/TileStache,jbants/TileStache,MetGIS/TileStache,Billups/TileStache,TileStache/TileStache