Add --file-cache-method and --no-file-sliding options.
Merge remote-tracking branch 'origin/no-cache-v0.3.2'

Conflicts:
	lib/pione/command/option.rb
	lib/pione/command/pione-broker.rb
	lib/pione/command/pione-client.rb
	lib/pione/command/pione-task-worker.rb