This prevents the libvlc object from having it's name set to
"memcpymmxext" by module_Need.
This reverts commit 15e7d182.

Casting to any other type would be (is?) unsafe as users can now freely
alias objects.

GCC will print a warning if the result of such function is ignored
This is useful for functions returning an allocated object (which
would leak if ignored), "getter" functions, and functions that are
"likely" to fail.

(Removed a unused macro)

Be carefull, it adds a new translated strings.

It fixes a regression introduced by fccf6aa0

It is provided for convenience for interfaces.

It may improve TS clock synchro algo.

Pointed-out-by: Sébastien Escudier

Crash happens if you do:
 - Play item
 - Activate vfilter
 - Stop item
 - Deactivate vfilter... BooM.
(cherry picked from commit c876401791144309d2427214d818a34198238358)