self deployment

[UnixJunkie]

when the mds is started, it should start all DSs too since it has the machines file
this is a sequence of scp then ssh

[UnixJunkie]

this is quite important for usability

[UnixJunkie]

also requires a --no-deploy option to disable the feature

[UnixJunkie]

We cannot much self deploy if the executable is not portable.
So this is related to #73.