Remove the "-f" script argument from the documentation

Closes #4778.
[SPEC] Created snapshot.* and nodes.* namespaces

Moved node_info, node_stats, shutdown and hot_threads into nodes.*
Moved snapshot and repository APIs into snapshot.*
Cleanup tests - using assert method instead of assert keyword
Remove `omit_term_freq_and_positions` for new indices

`omit_term_freq_and_positions` was deprecated in `0.20` and
is not documented anymore. We should reject indices that are
created with this option in the future.

Closes #4722
Add SecurityManger / policy when running tests.

This commit adds a security manager to the test JVMs
that prevents mainly writing files outside of the JVMs
current test directory.
[SPEC] Added missing body object in snapshot apis
Use millis for joda DateTimeFormatter.print()

Fixes #4782.
[SPEC] removing deprecated include/exclude for get_source

_source_include/_source_exclude should be used instead
Removed double masterNodeTimeout set in RestPutRepositoryAction
Bulk: Failed preparsing does not fail whole bulk request

If a preparsing of the source is needed (due to mapping configuration,
which extracts the routing/id value from the source) and the source is not
valid JSON, then the whole bulk request is failed instead of a single
BulkRequest.

This commit ensures, that a broken JSON request is not forwarded to the
destination shard and creates an appropriate BulkItemResponse, which
includes a failure.

This also implied changing the BulkItemResponse serialization, because one
cannot be sure anymore, if a response includes an ID, in case it was not
specified and could not be extracted from the JSON.

Closes #4745