The dark-bg scheme draws an explicit black background, so should also be
readable in terminals with a light background. That's been the main
show-stopper for enabling colors by default, as the 'dark' color scheme
is totally unreadable on light backgrounds and there's no way to detect
what background the terminal is actually using.

What a mess.

https://code.blicky.net/yorhel/ncdu/issues/153#issuecomment-764

(cherry picked from commit a076ac714aa6fb24e0e9eb227372df84a4b6000b)

(cherry picked from commit ef7b4e5c28739c26b3a120296f9dc2ddaf2d4375)

(cherry picked from commit e4e8ebd9e0037812436a1588809deb23e0f3751a)

Fixes #141

They were defined (rather than just declared) in .h files, when they
really should be defined in at most a single .c file.

Fixes #140.

This is a best-effort approach to save ncdu state when memory is low.
There's likely allocation in libraries that isn't being checked
(ncurses, printf).

Fixes #132 (it actually doesn't, that needs a 64bit static binary too,
but I'll get to that)

Fixes #128.

Symlink loops are handled by the stat(2) syscall. Symlinks pointing to a
directory are ignored (to avoid loops in the recursive scan).

https://dev.yorhel.nl/ncdu/bug/125

Ought to fix https://dev.yorhel.nl/ncdu/bug/115

https://dev.yorhel.nl/ncdu/bug/111

And document the --color flag that I forgot.

I've decided not to use ls-like file name coloring for now, instead just
coloring the difference between a (regular) file and a dir.

Still looking for a good color scheme for light backgrounds.

TODO:
- Add (ls-like) colors to the actual file names
  -> Implement full $LS_COLORS handling or something simple and custom?
- Test on a white/black terminal, and provide an alternate color scheme
  if necessary.
- Make colors opt-in?

Fixes https://dev.yorhel.nl/ncdu/bug/94

Key 'b' in the browse window spawns a shell in the current directoy.

We first check the $SHELL environment variable of the user for the preferred
shell interpreter. If it's not set, we fall back to the compile time
configured default shell (usually /bin/bash).

Signed-off-by: Thomas Jarosch <thomas.jarosch@intra2net.com>

Slightly modified patch from Gianluigi Tiesi.
http://dev.yorhel.nl/ncdu/bug/47

This is a slightly modified patch contributed at

  http://dev.yorhel.nl/ncdu/bug/35

Both microlibraries come from another source, and are not maintained as
part of ncdu. This separation of src/ and deps/ makes the relation more
clear.

Use a macro instead of the global constant `cachedir_tag_signature`.
Use `memcmp` instead of `strncmp`.
Add `has_cachedir_tag` to exclude.h.

(See http://dev.yorhel.nl/ncdu/bug/30)

A new command line parameter allows to filter out directories containing
the proper `CACHEDIR.TAG` file.
See http://www.brynosaurus.com/cachedir/

This also adds the possibility to combine short options that expect an
argument, e.g. "-xo <file>" or even "-xo<file>".

I've no idea for what other purpose I'd use numbered options. This is
much shorter, and can easily be combined with other options (e.g. -rx1).