Alpha version #2 of v0.2

Important: Hive v0.11 or later is required (or recommended) from this release.

A major enhancement for this pre-release is the support for iterative training using distributed cache.
Find examples in our wiki pages [1] [2].

Also, the returning value of cw/arow/scw is changed to return covariance as well.
See examples (e.g., this one) for details.

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• Enhancement
  • Supported a feature to load a prediction model ("-loadmodel" option) [e7ae2f1, e63a9fc]
  • Added rowid() and taskid() UDF [f0a688b]
  • Added distcache_gets UDF [3810923] [PR#64, PR#65]
  • Added extract_feature UDF [a984536]
• Major Changes
  • Modified to return covarinace in cw/arow/scw [e7ae2f1]
  • Added aliases for UDFs [8ee0586]
  • Changed hive version dependency to 0.11 or later [a856753, 96d7593]
• Minor Changes
  • Fixed UDFs to return Hive values instead of Java primitive values [71a3415]
  • Fixed '==' to 'equals' for HivemallConstants [c9c0291, 8d34ce5]
  • Fixed mhash UDF for arrays inputs [fa8efcb]
• Bugfix
  • Fixed a bug in multiclass PA [46da974]