build: include <strings.h> for strcasecmp()

It happens to work without strings.h on glibc or with _GNU_SOURCE, but
the POSIX standard requires including <strings.h>.

Hopefully fixes OSX build.

audio/out/ao_oss.c

@@ -33,6 +33,7 @@
 #include <fcntl.h>
 #include <errno.h>
 #include <string.h>
+#include <strings.h>
 
 #include "config.h"
 #include "options/options.h"

bstr/bstr.c

@@ -17,6 +17,7 @@
  */
 
 #include <string.h>
+#include <strings.h>
 #include <assert.h>
 #include <stdarg.h>
 #include <stdint.h>

demux/demux_lavf.c

@@ -18,12 +18,11 @@
  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  */
 
-// #include <stdio.h>
 #include <stdlib.h>
-// #include <unistd.h>
 #include <limits.h>
 #include <stdbool.h>
 #include <string.h>
+#include <strings.h>
 #include <assert.h>
 
 #include "config.h"

demux/demux_mf.c

@@ -18,6 +18,7 @@
 
 #include <stdio.h>
 #include <stdlib.h>
+#include <strings.h>
 #include <unistd.h>
 #include <sys/types.h>
 #include <sys/stat.h>

demux/demux_playlist.c

@@ -15,6 +15,8 @@
  * with mpv.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <strings.h>
+
 #include "common/common.h"
 #include "options/options.h"
 #include "common/msg.h"

input/keycodes.c

@@ -18,6 +18,7 @@
 
 #include <stddef.h>
 #include <string.h>
+#include <strings.h>
 
 #include "bstr/bstr.h"
 #include "common/common.h"

misc/charset_conv.c

@@ -21,6 +21,7 @@
 
 #include <stdlib.h>
 #include <errno.h>
+#include <strings.h>
 #include <assert.h>
 
 #include "config.h"

options/m_config.c

@@ -25,6 +25,7 @@
 #include <stdio.h>
 #include <errno.h>
 #include <string.h>
+#include <strings.h>
 #include <assert.h>
 #include <stdbool.h>
 

player/loadfile.c

@@ -18,6 +18,7 @@
 
 #include <stddef.h>
 #include <stdbool.h>
+#include <strings.h>
 #include <inttypes.h>
 #include <assert.h>
 

player/lua.c

@@ -17,6 +17,7 @@
 
 #include <assert.h>
 #include <string.h>
+#include <strings.h>
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <unistd.h>

player/scripting.c

@@ -16,6 +16,7 @@
  */
 
 #include <string.h>
+#include <strings.h>
 #include <sys/types.h>
 #include <dirent.h>
 #include <math.h>

stream/stream_dvd.c

@@ -23,6 +23,7 @@
 #include <string.h>
 #include <unistd.h>
 #include <string.h>
+#include <strings.h>
 #include <libgen.h>
 #include <errno.h>
 #include <stdint.h>

stream/stream_pvr.c

@@ -30,6 +30,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
+#include <strings.h>
 #include <sys/time.h>
 #include <errno.h>
 #include <sys/ioctl.h>

stream/tv.c

@@ -29,6 +29,7 @@
 #include <stdlib.h>
 #include <unistd.h>
 #include <string.h>
+#include <strings.h>
 #include <sys/time.h>
 #include <assert.h>
 #include <libavutil/avstring.h>

stream/tvi_v4l2.c

@@ -40,6 +40,7 @@ known issues:
 #include <pthread.h>
 #include <stdio.h>
 #include <string.h>
+#include <strings.h>
 #include <time.h>
 #include <sys/ioctl.h>
 #include <sys/mman.h>

sub/find_subfiles.c

@@ -1,5 +1,6 @@
 #include <dirent.h>
 #include <string.h>
+#include <strings.h>
 #include <stdlib.h>
 #include <assert.h>
 

sub/sd_srt.c

@@ -19,6 +19,7 @@
  */
 
 #include <string.h>
+#include <strings.h>
 #include <stdint.h>
 #include <stdlib.h>
 #include <stdio.h>