Add version to footer alongside the copyright message

(as with old http interface). Also added '-Lua Web Interface-'.

Adding the '-Lua Web Interface-' will give an easy way for applications to tell whether they are dealing with the old or new interfaces. The commands are somewhat different, so this is important.
Signed-off-by: Rémi Denis-Courmont <remi@remlab.net>
(cherry picked from commit eb2becab3fe2e0872a3b6f21a71b95f3e2fcd2e6)

share/lua/http/dialogs/footer

@@ -33,5 +33,5 @@ This dialog needs the following dialogs to be fully functional: <none>
   <a href="/flash.html">Flash based remote playback</a> -
   <a href="http://www.videolan.org">VideoLAN website</a>
   <br />
-  <?vlc print(vlc.misc.copyright()) ?>
+  <?vlc print(vlc.misc.version() .. " - Lua Web Interface - " .. vlc.misc.copyright()) ?>
 </div>