Patch by ale5000, on IRC. Close #3336

...unless proper reference counting si involved,
or the signal is blocking queued (but that is deadlock-prone).

Ref: LP#528285

This should fix LP#465560 - segmentation fault in strstr()

We only use getopt_long(). Also we don't care about pre-C89 compilers.

(We still need -lgnugetopt for cachegen)

This mostly reverts commit 37de4458.

Signed-off-by: Jean-Baptiste Kempf <jb@videolan.org>

Fix the bug where caching would stay all the time when stopping