Add dosbox recipe

recipes/dosbox/01_redox.patch

+--- source/include/cross_orig.h	2017-10-25 01:51:53.148610915 +0200
++++ source/include/cross.h	2017-10-25 00:56:43.896422986 +0200
+@@ -64,7 +64,7 @@
+ //Solaris maybe others
+ #if defined (DB_HAVE_NO_POWF)
+ #include <math.h>
+-static inline float powf (float x, float y) { return (float) pow (x,y); }
++//static inline float powf (float x, float y) { return (float) pow (x,y); }
+ #endif
+
+ class Cross { 

recipes/dosbox/recipe.sh

+VERSION=0.74
+TAR=https://sourceforge.net/projects/dosbox/files/dosbox/$VERSION/dosbox-$VERSION.tar.gz/download
+BUILD_DEPENDS=(sdl liborbital)
+
+export CFLAGS="-I$PWD/sysroot/include/SDL/"
+export CPPFLAGS="-I$PWD/sysroot/include/SDL/"
+export LDFLAGS="-L$PWD/sysroot/lib/"
+
+function recipe_version {
+    echo "$VERSION"
+    skip=1
+}
+
+function recipe_update {
+    echo "skipping update"
+    skip=1
+}
+
+function recipe_build {
+    ./autogen.sh
+    wget -O config.sub http://git.savannah.gnu.org/cgit/config.git/plain/config.sub
+    ./configure --host=${HOST} --prefix='' --disable-opengl --disable-sdltest --with-sdl-prefix="$PWD/../sysroot"
+    make
+    skip=1
+}
+
+function recipe_test {
+    echo "skipping test"
+    skip=1
+}
+
+function recipe_clean {
+    make clean
+    skip=1
+}
+
+function recipe_stage {
+    dest="$(realpath $1)"
+    make DESTDIR="$dest" install
+    skip=1
+}