It should be possible to putFiles, even though only a subset of the pillars are available

According to Kåre it is critical that the putFile client can be configured to allow ingest of files, even if pillars are unresponsive. The Identify phase will currently fail if pillar don't respond.

It should be configurable whether the putFile client should fail or continue if pillars aren't responding to IdentifyRequests. The default should be to continue.

In any case, if any of the defined pillars are unable to to complete the put successfully, the operation should be indicated to fail.