[TEST] relax size test, to not run into OOM
Added a check on moving bin & config plugin dirs

Plugins can contain bin & config sub-dirs that are copied to es's bin & config directories. If moving these directories fails we now throw an error.
[TEST] SuppressSysoutChecks on ElasticsearchPostingsFormatTest
[TEST] Mute PluginManagerTests#testLocalPluginInstallWithBinAndConfig
[STORE] Make a hybrid directory default using `mmapfs` and `niofs`

`mmapfs` is really good for random access but can have sideeffects if
memory maps are large depending on the operating system etc. A hybrid
solution where only selected files are actually memory mapped but others
mostly consumed sequentially brings the best of both worlds and
minimizes the memory map impact.
This commit mmaps only the `dvd` and `tim` file for fast random access
on docvalues and term dictionaries.

Closes #6636
[ENV] Release node env if initialization fails

If the node initialisation fails, make sure the
node environment is closed correctly and thus
all locks (on data directories) being properly released.

Closes #6715
added a fix to the PluginManagerTests to create config & bin dirs if they don't exist
[TEST] SuppressSysoutChecks on ElasticsearchTokenStreamTestCase
[DOCS] Fix typo in reference
[DOC] Added comprehensive documentation for the Ruby and Rails integrations
[TEST] Wait for primary allocations before restart

This commit ensures that all primaries are allocated before we
restart the node. If one primary is in post recovery when we
restart it will not be allocated otherwise.
Docs: Update plugins.asciidoc to fix typo

Changed the name of the European Environment Agency (from European Environmental Agency)

Closes #6807
Add local node to cluster state
Today, the tribe node needs the local node so it adds it when it starts, but other APIs would benefit from adding the local node, also, adding the local node should be done in a cleaner manner, where it belongs, which is right after the discovery service starts in the cluster service
closes #6811
[STORE]: Make use of Lucene build-in checksums

Since Lucene version 4.8 each file has a checksum written as it's
footer. We used to calculate the checksums for all files transparently
on the filesystem layer (Directory / Store) which is now not necessary
anymore. This commit makes use of the new checksums in a backwards
compatible way such that files written with the old checksum mechanism
are still compared against the corresponding Alder32 checksum while
newer files are compared against the Lucene build in CRC32 checksum.

Since now every written file is checksummed by default this commit
also verifies the checksum for files during recovery and restore if
applicable.

Closes #5924

This commit also has a fix for #6808 since the added tests in
`CorruptedFileTest.java` exposed the issue.

Closes #6808
[TEST] Subclass ElasticsearchTestCase in LoggingConfigurationTests
[TEST] Close TransportClient after it's used in BulkProcessorTests otherwise it will leave threads behind
[TEST] Do RollingUpgrade in BWC tests
[TEST] added ability to provide settings for external nodes in backwards compatibility tests

Closes #6809
[TEST] Wait for longer on slow nodes until replicating has kicked in
[STORE] Treat reading past EOF as an corrupted index when we fail to read segment infos