Use short variable name
Extract transformation logit for each query to a new sub class
Indent
Use instnace variable to share information for count mapper/reducer and records mapper/reducer
Split methods to build reducer and mapper for count and records
Reduce indent
Merge branch 'master' of github.com:groonga/fluent-plugin-droonga

Conflicts:
	lib/droonga/plugin/distributor/distributed_search_plan.rb