Upgrade to 0.20.6.

Changes:

http://www.elasticsearch.org/downloads/0-20-6/
Upgrade to 0.90.0.

This upgade requires a full cluster restart.

Changes: http://www.elasticsearch.org/downloads/0-90-0/

Conflicts:
	UPDATING
Merge pull request #108 from reallyenglish/tomoyukis

Upgrade to 0.90.0