supports legacy bash-style (lower-hyphen) format for key settings, e.g. private-key-file;
re-instates needed backwards compatibility following recent locations overhaul
Merge pull request #842 from ahgittin/fix/private-key-file

supports legacy bash-style (lower-hyphen) format for key settings
Location config from properties fixes

- use brooklyn.jclouds.* for locations
- transform lower-hyphen into lowerCamel properties
Fix publicKeyFile lookup, append ".pub"

- was not working for files starting with "~/"