Libdvdnav: bump to v6.0.0 (#3129)

* libdvdnav: bump to v6.0.0

* Create libdvdnav-6.0.0.patchset

* Delete libdvdnav-4.2.0.patch

* Delete libdvdnav-5.0.3.patchset

* Delete libdvdnav-4.2.0.recipe

* Delete libdvdnav-4.2.1.recipe

* Delete libdvdnav-5.0.3.recipe

media-libs/libdvdnav/patches/libdvdnav-4.2.0.patch

@@ -1,20 +0,0 @@
---- libdvdnav-4.2.0/configure.ac	2011-10-07 20:20:59.001572864 +0000
-+++ libdvdnav-4.2.0-haiku/configure.ac	2012-04-09 16:41:25.801112064 +0000
-@@ -143,7 +143,7 @@
-     THREAD_CFLAGS="-I/usr/local/include -D_THREAD_SAFE"
-     CFLAGS="$THREAD_CFLAGS $CFLAGS"
-     ;;
--  *mingw32* | *cygwin*)
-+  *mingw32* | *cygwin* | *haiku*)
-     ;;
-   *)
-     AC_CHECK_LIB(pthread, pthread_create,
-@@ -168,6 +168,8 @@
-   *os2*)
-     LDFLAGS="-no-undefined -Zbin-files $LDFLAGS"
-     ;;
-+  *haiku*)
-+  	;;
-   *)
-     AC_CHECK_LIB(c, dlopen,
- 	         DYNAMIC_LD_LIBS="",