fix IndexOutOfBoundsException on _all field without tokens and keyword analyzer

fix AllEntries to only compute boost when there are actually some Entries available for the _all field

Closes #4771
[TESTS] Mapping update might get applied before the first document is indexed on replica, so it is better not to check if the new field isn't available before re-indexing first document.
Documentation typo.
[TEST] Added create api (hardcoded) to REST tests suite as it has no spec but it's just a variation of the index api
Fix test bug: test expects at least one child document.
[TEST] Better fix for missing create spec

create is a shortcut to index with op_type=create that the clients support
Added base Request class for read operations that usually happen on the master but can be executed locally.
Added base TransportAction class for master read operations that execute locally or not depending on the request class (local flag).

Added support for local flag where missing, in a backwards compatible manner:
     - IndicesExistsRequest
     - GetAliasesRequest (get alias api, aliases exist api)
     - TypesExistsRequest
     - GetIndexTemplatesRequest (get template, template exists)
     - GetSettingsRequest
     - GetRepositoriesRequest
     - PendingClusterTasks

 Added parsing of the local flag where missing in Rest*Action.

 Updated SPEC adding local flag param where missing and added REST tests that contain use of the local flag where it was just added.

Closes #3345