Retrieve the swift version with recon

Adding a '/recon/version' in order to get the swift version

Change-Id: I7b7ddbe70abb87c6a3b1010ddefa09d0acc09710
Move parse search logic outside from builder

Dramatic part of RingBuilder.search_devs which parse a complex format
of a search device string moved to the swift-ring-builder script.
Instead, the search_devs has a simple interface to search devices.

blueprint argparse-in-swift-ring-builder

Change-Id: If3dd77b297b474fb9a058e4693fef2dfb11fca3d
Merge "Retrieve the swift version with recon"