Contribs: use dvdnav fork on github

Bored as hell of those crashes...

contrib/src/dvdnav/libdvdnav-searching.c-check-cellnr-before-indexing.patch

-diff --git a/src/searching.c b/src/searching.c
-index 3649e9d..0b5f22a 100644
---- a/src/searching.c
-+++ b/src/searching.c
-@@ -640,7 +640,11 @@ uint32_t dvdnav_describe_title_chapters(dvdnav_t *this, int32_t title, uint64_t
-       goto fail;
-     }
- 
--    cellnr = pgc->program_map[ptt[i].pgn-1];
-+    if ((cellnr = pgc->program_map[ptt[i].pgn-1]) == 0) {
-+      printerr("Cell new row cannot be 0");
-+      continue;
-+    }
-+
-     if(ptt[i].pgn < pgc->nr_of_programs)
-       endcellnr = pgc->program_map[ptt[i].pgn];
-     else

contrib/src/dvdnav/rules.mak

 # DVDNAV
 
-LIBDVDNAV_VERSION := 4.2.0
-LIBDVDNAV_URL := http://dvdnav.mplayerhq.hu/releases/libdvdnav-$(LIBDVDNAV_VERSION).tar.bz2
+# LIBDVDNAV_VERSION := 4.2.0
+# LIBDVDNAV_URL := http://dvdnav.mplayerhq.hu/releases/libdvdnav-$(LIBDVDNAV_VERSION).tar.bz2
+DVDNAV_GITURL := git://github.com/microe/libdvdnav
+LIBDVDNAV_VERSION := git
 
 ifdef BUILD_DISCS
 PKGS += dvdnav
@@ -10,15 +12,19 @@ ifeq ($(call need_pkg,"dvdnav"),)
 PKGS_FOUND += dvdnav
 endif
 
-$(TARBALLS)/libdvdnav-$(LIBDVDNAV_VERSION).tar.bz2:
-	$(call download,$(LIBDVDNAV_URL))
+$(TARBALLS)/libdvdnav-git.tar.xz:
+	$(call download_git,$(DVDNAV_GITURL))
 
-.sum-dvdnav: libdvdnav-$(LIBDVDNAV_VERSION).tar.bz2
+# $(TARBALLS)/libdvdnav-$(LIBDVDNAV_VERSION).tar.bz2:
+# 	$(call download,$(LIBDVDNAV_URL))
 
-dvdnav: libdvdnav-$(LIBDVDNAV_VERSION).tar.bz2 .sum-dvdnav
+.sum-dvdnav: libdvdnav-$(LIBDVDNAV_VERSION).tar.xz
+	$(warning $@ not implemented)
+	touch $@
+
+dvdnav: libdvdnav-$(LIBDVDNAV_VERSION).tar.xz .sum-dvdnav
 	$(UNPACK)
 	$(APPLY) $(SRC)/dvdnav/dvdnav.patch
-	$(APPLY) $(SRC)/dvdnav/libdvdnav-searching.c-check-cellnr-before-indexing.patch
 	$(MOVE)
 
 DEPS_dvdnav = dvdcss dvdread