Query DSL: Cache range filter on date field by default

A range filter on a date field with a numeric `from`/`to` value is **not** cached by default:

    DELETE /test

    PUT /test/t/1
    {
      "date": "2014-01-01"
    }

    GET /_validate/query?explain
    {
      "query": {
        "filtered": {
          "filter": {
            "range": {
              "date": {
                "from": 0
              }
            }
          }
        }
      }
    }

Returns:

    "explanation": "ConstantScore(no_cache(date:[0 TO *]))"

This patch fixes as well not caching `from`/`to` when using `now` value not rounded.
Previously, a query like:

    GET /_validate/query?explain
    {
      "query": {
        "filtered": {
          "filter": {
            "range": {
              "date": {
                "from": "now"
                "to": "now/d+1"
              }
            }
          }
        }
      }
    }

was cached.

Also, this patch does not cache anymore `now` even if the user asked for caching it.
As it won't be cached at all by definition.

Added as well tests for all possible combinations.

Closes #7114.

(cherry picked from commit 9e68687)
Test: Allow CliTool to write out stacktraces

In order to have the possibility of debugging on the command line, the user
now can either set the es.cli.debug system property
which results in stack traces being written to to the terminal.

Closes #7222
Java client API: CreateIndexRequestBuilder.addMapping throws IllegalStateException if you add same type more than once

Previously, it would silently overwrite the previous mapping, which was trappy.

Closes #7231

Closes #7243
Core: Store index creation time in index metadata

This change stores the index creation time in the index metadata when an index is created.  The creation time cannot be changed but can be set as part of the create index request to allow for correct creation times for historical data.

Closes #7119
Internal:  adjusted visibility to package private for BroadcastShardOperationRequest subclasses and their constructors

Also replaced the String,int pair for index and shard_id with ShardId object that holds the same info and serialized it the same way too.

Closes #7235