Fix 1d freeze bug

Matlab insidiously produces a square matrix in `repmat` when the `[m n p...]`
vector turns out to be a scalar.
Fix 3d read bug

`scanf` only handles 1d and 2d. 3d needs a manual `reshape`.
Fix no date bug

`scanf` really wants to advance past newlines if the current line contains only
whitespace. So read the line first, then parse it.
Fix output format of floating point numbers

A crazy as it sounds, in Ufiles there is no space between successive floating
point numbers when they are negative.