The language keeps changing when I'm not looking!

I truly didn't realise this wasn't already done until someone sent me a .BMP file.

Also, rename old 'lines' view to 'details' which makes more sense

Grid view

- Lifetime changes in unix.rs
- lexical_ordering -> cmp
- from_utf8_lossy got moved into String
- vec.get(n) -> vec[n]

Fix build with rust master

- change to_string() on numbers to to_str()

This makes it more like ls. The --long (-l) argument has been added to get at the old behaviour, and the --links argument is now on -H. I can't crib this behaviour from ls because it shows it by default.

TODO: The terminal size is currently assumed to be 80, and it uses the string length, rather than the width.