ParseField: Support for when all fields are deprecated

Closes #8067
Docs: fixed typo in documentation

Closes #8205
Docs: rolling upgrade process seems incorrect

When reading the [rolling upgrade process](http://www.elasticsearch.org/guide/en/elasticsearch/reference/current/setup-upgrade.html#rolling-upgrades), you can see that we wrote:

* disable allocation
* upgrade node1
* upgrade node2
* upgrade node3
* ...
* enable allocation

That won't work as after a node has been removed and restarted, no shard will be allocated anymore.
So closing node2 and remaining nodes, won't help to serve index and search request anymore.

We should write:

* disable allocation
* upgrade node1
* enable allocation
* wait for shards being recovered on node1
* disable allocation
* upgrade node2
* enable allocation
* wait for shards being recovered on node2
* disable allocation
* upgrade node3
* enable allocation
* wait for shards being recovered on node3
* disable allocation
* ...
* enable allocation

I think this documentation update should go in 1.3, 1.4, 1.x and master branches.

Closes #8218
Closes #7973.
Catch both FileNotFound & NoSuchFileException
Test: testRecoverFromPreviousVersion should refresh from new nodes if running against v<1.3.0

This is due to a bug in older version causing refreshes to potentially be missed due to relocations #6545

Also:
- Changed test to keep track of ids and report missing ones.
- Removed total count check from assertSearchHits in order to enable per id checks in cased of a mismatch
- Added a printable unique id part the ids of dummy documents added by indexRandom. The current random unicode id
  sometimes prints as ???? to the logs making them hard to trace
[TEST] `Scope.SUITE` is not reproducible due to late cluster initialization

The cluster for `Scope.SUITE` tests must be initialize in a static manner
before the first test runs otherwise the random context used to initialize
the cluster is taken from tests randomness rather than the suites randomness.
This means test clusters will have different setups if only a single test is
executed or even the test might have a entirely different random sequence.
added tests
better test names