conveniences and tweaks for software process tasks such as ssh, including isPidRunning etc; also CommonCommands.fail(...) which generates good error messages
introduce TaskAdapter and rename HasTask to TaskWrapper, to simplify API; and introduce TaskFactory,
so that SSH tasks can be easily reused
restructuring of SshTasks, to be in own directory, mostly independent of Brooklyn things
(still leans on SshMachineLocation; that could be easily generalised however); also rename CommonCommands to BashCommands

lots of changes e.g. moving to BashCommands, but nothing very interesting!
restructuring of how tasks in drivers are loaded, for use as tasks outside drivers (e.g. for chef)