Added a ClusterHealthResponse.toString implementation for better error reporting in FullRollingRestartTests timeout failures.
Assert on failures in QueryRescorerTests
Make ContextIndexSearcher delegate more method calls to Engine.searcher().

When running tests, Engine.searcher() is going to be an AssertingIndexSearcher
so we definitely don't want to discard it. This commit fixes it as well as the
bugs it found.

Closes #3987
rename and document "index.mapping.date.parse_upper_inclusive" setting for date fields

The setting causes the upper bound for a range query/filter to be rounded up,
therefore the name `round_ceil` seems to make more sense.

Also this commit removes the redundant fourth parameter to DateMathParser.parse(..)
which was never used.
was:    parse(String text, long now, boolean roundUp, boolean upperInclusive)
is now: parse(String text, long now, boolean roundCeil)

closes #3914
Add version to prebuilt analyzers

This patch takes the version of the created index into account when a
prebuilt analyzer is created.
So, if an index was created with 0.90.4, then the prebuilt analyzers
will be the same than on the 0.90.4 release.

One reason for this feature is the possibility to change pre built
analyzers like the standard one.

The patch tries to reuse analyzers as mutch as possible. So even if
version X.Y.Z and X.Y.A use the same lucene analyzers, the same instance
is reused in order to prevent overcreation of lucene analyzer instances.

Closes #3790
Making unit test future proof by using old version, in case versions change
Add the 'recovery' _cat API endpoint

This addes the _cat/recovery/{index} API endpoint, which displays
information about the status of recovering shards. An example of the
output:

index shard node                   target    recovered     %
test2 0     Fwo7c_6MSdWM0uM1Ho4t-g 147304414  19236101 13.1%
test  0     Fwo7c_6MSdWM0uM1Ho4t-g 145891423 119640535 82.0%

Fixes #3969
mget API should support global routing parameter

mget API support `_routing` field but not `routing` parameter.

Reproduction here:

```sh
curl -XDELETE "http://localhost:9200/test/"; echo
curl -XPUT "http://localhost:9200/test/" -d'{
   "settings": {
      "number_of_replicas": 0,
      "number_of_shards": 5
   }
}'; echo

curl -XPUT 'http://localhost:9200/test/order/1-1?routing=key1' -d '{
   "productName":"doc 1"
}'; echo
curl -XPUT 'http://localhost:9200/test/order/1-2?routing=key1' -d '{
   "productName":"doc 2"
}'; echo
curl -XPUT 'http://localhost:9200/test/order/1-3?routing=key1&refresh=true' -d '{
   "productName":"doc 3"
}'; echo

curl -XPOST 'http://localhost:9200/test/order/_mget?pretty' -d '{
    "docs" : [
        {
            "_index" : "test",
            "_type" : "order",
            "_id" : "1-1",
            "_routing" : "key1"
        },
        {
            "_index" : "test",
            "_type" : "order",
            "_id" : "1-2",
            "_routing" : "key1"
        },
        {
            "_index" : "test",
            "_type" : "order",
            "_id" : "1-3",
            "_routing" : "key1"
        }
    ]
}'; echo

curl -XPOST 'http://localhost:9200/test/order/_mget?pretty&routing=key1' -d '{
	"ids": [
		"1-1",
		"1-2",
		"1-3"
	]
}'; echo
```

Closes #3996.
Fix String.format to use Locale.ROOT in RestRecoveryAction
Fixed test cluster scope to be able to run it multiple times if needed
Add a GetFieldMapping API

This new API allows to get the mapping for a specific set of fields rather than get the whole index mapping and traverse it.
The fields to be retrieved can be specified by their full path, index name and field name and will be resolved in this order.
In case multiple field match, the first one will be returned.

Since we are now generating the output (rather then fall back to the stored mapping), you can specify `include_defaults`=true on the request to have default values returned.

Closes #3941