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
Geo: fixes computation of geohash neighbours

The geohash grid it 8 cells wide and 4 cells tall. GeoHashUtils.neighbor(String,int,int.int) set the limit of the number of cells in y to < 3 rather than <= 3 resulting in it either not finding all neighbours or incorrectly searching for a neighbour in a different parent cell.

Closes #7226
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
Remove `numeric_range` filter

As done with #4034, `numeric_range` filter has been deprecated since 1.0.0.

Closes #7108.
[DOCS] mention the type of caches that warmers load
Fix: VerboseProgress(PrintWriter) does not set the writer
Tests: move plugin dir to plugins dir

We should be consistent in our naming for classes and resources.
Update api & Indices stats: fixed version checks for no-op updates which got in after 1.3 was released

Also added basic bw comp test for indices stats api.

Relates to #6822
A content decompressor that throws a human readable message when
compression is disabled and the user sends compressed content.
Add GroovyCollections to the sandbox whitelist

Also clarify in the docs that changing the whitelist/blacklist settings
replace the list, they don't add to it.

Fixes #7089
Fixes #7088
Forbid index names over 100 characters in length

Fixes #4417
Add [1.3.3] and [1.2.5] version constants.