Merge topic branch t/ls-l into master

A single commit which deprecates the chunk table and mbox listing
modes. The chunk table can still be listed with para_afh(1), and the
mbox format was never really useful to begin with. The idea is to
remove support after 0.8.0 has been released.

Cooking for three months.

* refs/heads/t/ls-l:
  server: Deprecate -l=c and -l=m of com_ls().

diff --cc NEWS.md
index 416f99c66894badcd781d46e8e31b8a5e544c0f8,d5812289640d71c52a60bd850928c72b3c5ba0b8..935e8493cedeb4c3c94ffafbb4c6d11035ea65f4
--- 1/NEWS.md
--- 2/NEWS.md
+++ b/NEWS.md
@@@ -5,13 -5,6 +5,15 @@@ NEW
  0.7.4 (to be announced) "genetic contraction"
  ---------------------------------------------
  
-   performance of para_play for large mp3 mp4 files.
- 
 +- Simplification of the build system. The only visible effect is
 +  that configure no longer prints a summary at the end.
 +- para_play is no longer built if libreadline is not installed.
 +- Speedups for the buffer tree code, which particularly improves the
++  performance of para_play for large mp3 files.
++- The chunk table and mbox listing modes of the ls server command
++  have been deprecated. They still work, but a warning is issued to
++  inform the user about the deprecated option.
 +
  Downloads:
  [tarball](./releases/paraslash-git.tar.xz)