Fix also minor bug in zone filtering when zone set to 0.
Moved bin/swift-recon to swift/cli/recon.py, which makes
it possible to import it without using some scary hacks.
bin/swift-recon is now created by setup.py install.
Closes-Bug: #1261692
Change-Id: Id0729991c8ece73604467480dbf93fec7d8eb196