Log Message:
Update groonga to 4.0.8.

Release 4.0.8 - 2014/11/29
--------------------------

Improvements
^^^^^^^^^^^^

* [deb] Supported Ubuntu 12.04 again because Travis-CI runs on it.
* [mruby] Supported pretty print - ``"pp"`` for debugging. And supported to
  show internal objects more descriptive format when inspecting it.
* Supported full text search query without index if one column is specified
  for ``--match_columns`` even though sequential search is executed
  by ``--query`` and ``--match_columns`` combination.
  [groonga-dev,02902] [Reported by Atsushi Shinoda]
* [experimental] :doc:`/reference/functions/in_values` supports auto sequential
  search mode. There is a case that sequential search is faster than index \ 
search when
  the number of narrowed down records is small enough in contrast to
  the number of expected records to narrow down by ``in_values`` with
  ``AND`` operation which use indexes.
  The value of ``GRN_IN_VALUES_TOO_MANY_INDEX_MATCH_RATIO`` is used as
  threshold whether Groonga execute sequential search or search with indexes in
  such a case.
* [mruby] Supported to load relative path of script.
* Supported test suite to write query optimizer test more easily with
  mruby enabled build.
* Supported offline index construction for token filters.
  [GitHub#239] [Patch by Naoya Murakami]
* [experimental] :doc:`/reference/functions/between` supports auto sequential \ 
search mode.
  Use the value of ``GRN_BETWEEN_TOO_MANY_INDEX_MATCH_RATIO`` as threshold.
  Basic concept is similar to ``GRN_IN_VALUES_TOO_MANY_INDEX_MATCH_RATIO``.
* [experimental] Supported multiple drilldowns for :doc:``/reference/command/select``
  command. The syntax is extended to support this feature. The new one is
  ``--drilldown[LABEL1].keys COLUMN1,COLUMN2`` for keys,
  ``--drilldown[LABEL1].output_columns _value.COLUMN1,_value.COLUMN2,_nsubrecs`` \ 
for output columns.
  In the previous versions, a client application must implement by oneself for \ 
drilldown
  by multiple keys. Use ``_key[N]`` for ``--drilldown[LABEL1].output_columns`` \ 
to show
  original value of key in records.
* Supported to search ``'reference_column @ "query"'`` without index.
* [experimental] Added :doc:`/reference/commands/range_filter` command. It is \ 
faster than select
  command to fetch specific range of records in most cases, because it doesn't \ 
returns
  the number of matched records. There are limitations which doesn't support \ 
drilldown and so on.
  Thus, ``range_filter`` is suitable for extracting first ``N`` records in \ 
specific range for ranking
  or something else.
* [httpd] Supported ``groonga-httpd`` on windows.
* Supported vector column for drilldown.
* [deb] Changed ``groonga-httpd`` as default HTTP server package.
  ``groonga-server-http`` is deprecated. Note that \ 
:doc:`/reference/executables/groonga-server-http`
  functionality itself is still exists in Groonga. If you just want to use \ 
simple HTTP server
  in traditional way, specify proper arguments by command line for \ 
:doc:`/reference/executables/groonga`.
* Added configuration file for Windows CI on AppVeyor.
  [groonga-dev,02970,02981] [Patch by Hiroshi Hatake]

Fixes
^^^^^

* [doc] Fixed duplicated execution example path about
  :doc:`/reference/commands/table_create`.
  [GitHub groonga.org#14] [Reported by Masafumi Yokoyama]
* Fixed a bug that nested indexed full text search against ``X._key``
  returns empty results.
* Fixed flags parameter which is strict in BSD ``mkostemp(3)``.
  [GitHub#240] [Patch by Jun Kuriyama]
* Fixed a bug that select command reports invalid value type (table)
  as index column value type. It was fixed to ``UInt32``.
  Note that it affects only the value of response header.
  The search results is not changed at all.
* Fixed a bug that compare operations such as ``<``, ``<=``, ``>``, \ 
``>=``, ``!=`` with
  Time and String type returns invalid results.
* Fixed a bug that prefix search can't be executed against single character such as
  ``"x*"``. [GitHub#242] [Patch by Naoya Murakami]
* Fixed a memory leak on drilldown ``ShortText`` value with ``--filter``.
* Fixed missing ``","`` for ``"DDL:set_token_filters"`` log.
  [Reported by Naoya Murakami]

Thanks
^^^^^^

* Atsushi Shinoda
* Masafumi Yokoyama
* Naoya Murakami
* Jun Kuriyama
* Hiroshi Hatake