Log Message:
Update databases/elasticsearch to 2.0.0.

Breaking changes
- Remove option to configure custom config file via CONF_FILE
  or -Des.default.conf

Deprecations
- Deprecate index.analysis.analyzer.default_index in favor
  of index.analysis.analyzer.default.

Enhancements
- Make PerThreadIDAndVersionLookup per-segment
- TransportNodesAction shouldn't hold on to cluster state
- Packaging: change permissions/ownership of config dir
- Release: Fix package repo path to only consist of major version
- Plugin Cloud GCE: Add _gce_ network host setting
- Check "plugin already installed" before jar hell check.
- Plugin script to set proper plugin bin dir attributes
- Plugin script to set proper plugin config dir attributes

Bug fixes
- CRUD: Send response for update request when it timed out
- Engine: Never wrap searcher for internal engine operations
- Fielddata: Add GeoPoint in StreamInput/StreamOutput
- Properly bind ClassSet extensions as singletons
- Streamline top level reader close listeners and forbid
  general usage
- Settings in log config file should not overwrite custom parameters
- Plugin cli tool should not create empty log files
- Mappings: Enforce metadata fields are not passed in documents
- Plugin Cloud AWS: Discovery-ec2 plugin should check discovery.type
- Parse Java system properties in plugin.bat
- PluginManager: Dont leave leftover files on unsuccessful installs
- REST: Restore support for escaped '/' as part of document id
- REST: Add missing REST spec for detect_noop
- REST: Expose nodes operation timeout in REST API
- REST: Ensure XContent is consistent across platforms
- Shadow Replicas: Don't pull translog from shadow engine
- Snapshot restore operations throttle more than specified

Upgrades
- Upgrade Netty to 3.10.5.final

NOT CLASSIFIED
- [DOCS] terminate_after is not experimental anymore
- Remove unused clear(IndexReader) method from IndexFieldData
- changed ben to been
- move render search template methods to cluster admin client
- Docs: Document ES_CLASSPATH removal in breaking changes
- Rewrite native script documentation
- Docs: Update repository docs with new major version structure
- Add a note about shard failure in the api