This adds an 'm' command to show the latest modified time of all files
in a directory. The 'M' command allows for ascending and descending
mtime sorting. These are only enabled with the -e flag and overload
the dir_ext mtime field.
Turns out that being able to open an empty directory actually has its
uses:
- If you delete the last file in a directory, you now won't be directed
to the parent directory anymore. This allows keeping 'd' pressed
without worrying that you'll delete stuff outside of the current dir.
(This is the primary motivation for doing this)
- You can now scan and later refresh an empty directory, as suggested by
#2 in http://dev.yorhel.nl/ncdu/bug/15
Here is the new multi-page listing functionality I promised in
5db9c2aea1.
It may look very easy, but getting this to work right wasn't,
unfortunately.
This optimizes a few actions (though not all), and makes the code easier
to understand and expand.
The behaviour of the browser has changed a bit with regards to
multi-page listings. Personally I don't like this change much, so I'd
probably fix that later on.
