Location config from properties fixes

- use brooklyn.jclouds.* for locations
- transform lower-hyphen into lowerCamel properties

This builds on Alex's merged pull request (https://github.com/brooklyncentral/brooklyn/pull/842).

It changes where we convert from deprecated to the desired key format. Now it does it in the JcloudsPropertiesFromBrooklynProperties and the LocalhostResolver, rather than in the LocationConfigUtils.getKeyData - by the time it calls that, the config should be in the desired form.

It builds up a mapping of key names to be converted, in each resolver. Before the keys are passed to the `JcloudsLocation` or `LocalhostMachineProvisioningLocation`, the keys are converted (in a method named `transformDeprecated`, to make it very clear).

We now support (in reverse order of preference - so last one present in this list is used):
* brooklyn.jclouds.private-key-file
* brooklyn.jclouds.privateKeyFile
* brooklyn.jclouds.aws-ec2.private-key-file
* brooklyn.jclouds.aws-ec2.privateKeyFile
* brooklyn.location.named.myloc=aws-ec2
* brooklyn.location.named.myloc.private-key-file
* brooklyn.location.named.myloc.privateKeyFile