Conflicts:
	Cargo.lock

This prevents crates.io from doing weird things from a circular depedency, which is probably my fault.

It kept on using 0.1.1, which didn't actually compile.

Otherwise, just display the hour and minute.

Add options -u, -U, and -m as shorthand options for displaying different
types of timestamp, not just one. It's possible to have more than one by
specifying more than one of these shorthands, but *not* when used with
--time, as this is only meant to display one at a time.

Using the datetime crate, add an extra column to the --long view that
prints out the modified, accessed, or created timestamp for each file.
Also, let the user pick which one they want to see based on the --time
command-line option.

- std::os -> std::env

- Turn the views and main program loop into structs, rather than just as one gigantic function
- Separate views into their own files

The addition of the git column and the tree view meant that a lot of functions now just took extra arguments that didn't seem to fit. For example, it didn't really work to have only one 'view' method that printed out everything, as the different view options now all take different parameters.

See RFC 235

Using `retain` instead of `filter` means we can just re-use the same Vec.

This commit has been brought to you by Unicode Box-Drawing Characters!

FileName was always a special-cased column, as it was assumed to be the last column in the output. Now, it's explicitly marked as such. This allows the hash marks to be placed before the filename, rather than at the start of the line.

There's still a lot to do, but this is actually *something*. The tree hierarchy is displayed using hashes at the start of a line. I want to have it just before the filename, but this will need some changes to the way that columns are handled.

Now there are no more unwrap()s!

You can now have different columns per directory. So now, the Git column only appears when there's a Git repository in the current directory.

- Rename std::io to std::old_io