This should fix https://dev.yorhel.nl/ncdu/bug/99 - with the downside
that this requires a C99 compiler.
I also replaced all occurrences of static allocation of struct dir with
use dynamic allocation, because I wasn't really sure if static
allocation of flexible structs is allowed. In the case of dirlist.c the
dynamic allocation is likely required anyway, because it does store a
few bytes in the name 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
Rather than storing a pointer to another memory allocation in the
struct. This saves some memory and improves performance by significantly
decreasing the number of calls to [c|m]alloc() and free().
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.
