Handle X-Copy-From header in container_quota middleware

Content length of the copied object is checked before
allowing the copy request according to the container quota.

Closes-Bug: #1201875
Change-Id: If44b916791e94ac6c66eee04a5727186ce0e56ae
Merge "Handle X-Copy-From header in container_quota middleware"
return value on memcache client decr call

Closes-Bug: 1238204
Change-Id: I7d2ece118159637e5c5bf4bf5dd4ce4d2f6e4523
Removes vim comment

Change-Id: Ibc930638ee2d839e8499a13018c205b615f8b854
Partial-Bug: 1229324
Merge "Removes vim comment"