upstart support for controlling ElasticSearch

on Ubuntu, the default init daemon is upstart. We'd like to support it,
so here's a first attempt in that direction.

We're basing the general startup on Debian's sysV init script.
Merge commit '3a75a3021188914cf65e532fef8badb9236da4f5' into IT-7388-01
IT-7388-01 -- removes the -d option from the init.d script; ES pre-1.0 started in the background by default, ES post-1.0 starts in the foreground by default; hence the -d; however, the start-stop-daemon command is using -b to force the daemon into the background regardless, so it is unnecessary
Merge pull request #1 from assistly/IT-7388-01

It 7388 01