Adding support for fixed-width floating-point and integer array values.

As per issue #400.
Also, the numbers are left-justified. This looks correct when printing non-array values (you get something like `seq: 456`), but admittedly looks a little strange with arrays (e.g., `[5      ,      3      , 345   , 291231]`). Right-justification also looks strange, but for the opposite reason. I can handle each case differently, but it's up to you.