make more easily cloneable for people behind firewalls
treat IndexAlreadyExistsException more robustly

it seems that since ES 0.90.6 the error is:
"IndexAlreadyExistsException[[graphite_metrics] already exists]"
whereas it used to be:
"IndexAlreadyExistsException[[graphite_metrics] Already exists]"

now we just check for "IndexAlreadyExistsException" which should
suffice
update ES instructions. should work fine with 0.90.x