Update to 0.20.5 and switch to useing OpenJDK 7.

Changes: http://www.elasticsearch.org/download/2013/02/14/0.20.5.html

Conflicts:
	UPDATING
Fix jar file name introduced in update.

Submitted by:	zi
require OpenJDK 7

in accordance with elasticsearch. see commit
c077744e02607e9e25e1f111cad144164caae1a7