Release 0.2.2.

commit 3acf1f03fae615107d9d219ce7b23807aa0825b7
Author: HARUYAMA Seigo <haruyama@unixuser.org>
Date:   Sat Mar 15 14:25:24 2014 +0900

    Update Lucene. Add org.slf4j/slf4j-nop.

commit 02c12b73e87166df6b66a07bae556ca398a10fd9
Author: HARUYAMA Seigo <haruyama@unixuser.org>
Date:   Fri Feb 14 19:40:05 2014 +0900

    suppress eastwood warnings.