Log Message:
Update ruby-json and ruby-json-pure pacakge to 1.6.3.

2011-12-01 (1.6.3)
  * Let JSON.load('') return nil as well to make mysql text columns (default to
    '') work better for serialization.
2011-11-21 (1.6.2)
  * Add support for OpenStruct and BigDecimal.
  * Fix bug when parsing nil in quirks_mode.
  * Make JSON.dump and JSON.load methods better cooperate with Rails' serialize
    method. Just use: serialize :value, JSON
  * Fix bug with time serialization concerning nanoseconds. Thanks for the
    patch go to Josh Partlow (jpartlow@github).
  * Improve parsing speed for JSON numbers (integers and floats) in a similar way to
    what Evan Phoenix <evan@phx.io> suggested in:
    https://github.com/flori/json/pull/103
2011-09-18 (1.6.1)
  * Using -target 1.5 to force Java bits to compile with 1.5.