extend common commands so it can download to stdout; also update some of the Location usages to use specs, simplify that with LocalhostMachineProvisioningLocation.spec(), and create new test for new way of provisioning locations; and finally, restructure SshTasks to be a bit more intuitive
fix use of alternatives command, and various other tidies to CommonCommands;
start to migrate some to SshTasks, and convert postgresql and nginx to use them a bit better;
now better logging if sudo fails, and postgresql does a better job of installing and linking himself
(and starts to use quite a bit of guava / functional style)