Update couchdb.init script to match 1.5.0 version.

Sourced from /blob/master/etc/init/couchdb.tpl.in
That file was last edited in May 2012, so this script should work on
couchdb releases as far back as 1.2.x

Also seems to address the nohup added in
commit bc0a6d0cd2664807a13c369707987a98b310e057
Bump version to 2.5.3 for testing purposes