* remove mapkeeper and voldemort from command help, since we don't build them
* fix ordering of modules in root pom

closes #328

the existing YCSB API to generate time series data (numeric values associated
with timestamps).
See the TimeSeriesWorkload.java class Javadocs for details on how to use it
with a client and workloads/tsworkload_template for parameters.
Also add the BasicTSDB instance for printing/debugging the workloads.

This commit is an initial cut at a complete implementation using the
low-level Elasticsearch REST client.

[hbase12] Add HBase 1.2+ specific client that relies on the shaded client artifact provided by those versions. (#970)

[arangodb] Add ArangoDB Support

[scripts] Add mvn build if necessary for source checkout on windows.  Plus a couple other fixups to make consistent with the linux script.

Note the Guava classes in the test directory for AsyncHBase. These are there
as AsyncHBase uses Guava >= 18 while HBase and the mini cluster use Guava 12.

[riak] Done some code/comments cleanup.

the native Protobuf GRPC based API.

Added new binding for Riak, based on the one created by Basho Technologies (available at https://github.com/basho-labs/YCSB/tree/master/riak).

Change made to the original version:

- Made compatible with the latest YCSB version.
- Removed unused Constants.java file.
- Added strong consistency test support.
- Done some refinements to the code.
- Removed many unused function in the RiakUtils.java file.
- Choosed to use executeAsync methods to resolve a bug that didn't allow the benchmark to end whenever one or more nodes of the cluster are killed.
- Added TIME_OUT status return code.

To do:
- Add different LOG errors (i.e. insufficient_vnodes_available, ring_not_ready, etc.) - for references, check page http://docs.basho.com/riak/latest/ops/running/recovery/errors/#Errors-and-Messages
- ...

This commit fixes the Elasticsearch name throughout the YCSB benchmark
project from "ElasticSearch" to "Elasticsearch".

updating readme

updating package info

perfecting logic for http solr clients for all operations

renamed properties, tested cloud mode and cleaned code

removed dependency on dynamic field names, updated readme

now enforcing checkstyle

adding solr artifact

removing test cases relying on external dependencies

removed unused maven dependencies, added batch mode support, all try blocks now catch eplicit exceptions, Query/UpdateResponse status codes are handled more granularly, updated readme, added sample schema.xml file to support default field names in ycsb client, updated all license headers to 2016, using SolrClient object as primary client type regardless if Solr is running in Cloud or Stand-alone mode

cleaned code and config files, now accepting a solr base url property, simplified sample schema.xml file, renamed class to SolrClient, now updating documents atomically, added batch support to delete method

updated new line spacing of pom file comments

removed sample schema file, updated readme with more indepth explanation on running/setting up the solr-binding

removed some code lines no longer in use

renamed zookeeper param name, now throwing caught exceptions where appropriate, debug messages are now being logged on stderr

now returning an appropriate error if we receive an unexpected response from solr server, repeated calls to getResults is no longer

now using singletonMap to store update params in, fixed typo and missing id field in sample config in README

The memcached support was extracted from PR #98 by @jbellis, with cleanups to
bring it in line with current APIs and style guide.

This PR also addresses issue #326.

* Handles missing "java" with an error message.
* Adds a check_output method for users running on Python 2.6.
* Prints an error when importing argparse fails (third party module on Python 2.6).

This reverts commit 0e5866eb.

Restores #372

Add a DB client for Google Cloud Datastore. This initial commit includes implementation of all CRUD operations (modulo scan), and integration into the rest of YCSB (pom.xml changes, etc)

Next few commits will include Scan/query support, single entity group support, and better documentation.