Brooklyn Install Script

Updates to #157 to enable install on EC2 Ubuntu and other hosts that do not have remote root access, and better detection of remote hostname for checking liveness.
```
$ ./brooklyn-install.sh -s -u brooklyn -r ubuntu -k ~/.ssh/id_rsa-adk ec2-54-220-221-225.eu-west-1.compute.amazonaws.com
Installing Brooklyn 0.7.0-M1
Checking 'ec2-54-220-221-225.eu-west-1.compute.amazonaws.com:22' SSH connection......ok!
Installing prerequisite packages......done!
Installing Java 7 packages......done!
Creating 'brooklyn' user......done!
Setting up 'brooklyn' user......done!
Downloading Brooklyn distribution......done!
Configuring Brooklyn properties......done!
Installing examples and configuring catalog......done!
Starting Brooklyn...............done!
Brooklyn Console URL is http://ec2-54-220-221-225.eu-west-1.compute.amazonaws.com:8081/
Checking Brooklyn connection......success!
```
I think it is safer for the time being