Cleanup: fix names of recipe and patch files.

* this fixes the wrong recipe names introduced by myself in #d525fee
* adjust patch names to match corresponding recipes
* additionally: create 'additional-files' folders as hint to some
  ports that do not have a proper recipe yet

media-libs/sdl_mixer/sdl_mixer-1.2.12.recipe

@@ -0,0 +1,36 @@
+DESCRIPTION="Simple Direct Layer Mixer Library" 
+HOMEPAGE="http://www.libsdl.org/projects/SDL_mixer/" 
+SRC_URI="http://www.libsdl.org/projects/SDL_mixer/release/SDL_mixer-1.2.12.tar.gz"
+CHECKSUM_MD5="e03ff73d77a55e3572ad0217131dc4a1"
+REVISION="1"
+STATUS_HAIKU="stable"
+DEPEND="libsdl >= 1.2.14
+	media-libs/flac >= 1.2.1
+	media-libs/libmad >= 0.15.1
+	media-libs/libvorbis >= 1.3.1
+	media-libs/libmikmod >= 3.1.11
+	media-libs/libogg >= 1.2.0
+	media-libs/smpeg >= 0.4.5"
+
+BUILD()
+{
+	cd SDL_mixer-1.2.12
+	libtoolize --force --copy --install
+	aclocal --install -I acinclude
+	./autogen.sh
+	MANDIR=`finddir B_COMMON_DOCUMENTATION_DIRECTORY`/man
+	LIBDIR=`finddir B_COMMON_LIB_DIRECTORY`
+	./configure --prefix=`finddir B_COMMON_DIRECTORY` \
+		--libdir=$LIBDIR \
+		--mandir=$MANDIR \
+		--enable-music-midi
+	make
+}
+
+INSTALL()
+{
+	cd SDL_mixer-1.2.12
+	make install
+}
+LICENSE="Zlib"
+COPYRIGHT="1997-2012 Sam Lantinga"