Increased the timeout period for SOWF arming from 10 secs to 1 min.
Moved the install directory for powerpc.make.

This is more appropriate for tenzing.sma so it will remain that way.
The ROACH2's root directory should be mounted on tenzing.cfa to match
this when I get back to Cambridge.
Added a new TBS plugin for doing astrometry at the SMA.

Currently this just has some functions for getting and setting
the "constant" delay and phase offsets but will eventually provide
the fringe-stopping feature.