Indicate system includes for relevant SDL headers

src/hardware/ipx.cpp

@@ -16,11 +16,12 @@
  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
 
-
 #include "dosbox.h"
 
 #if C_IPX
 
+#include <SDL_net.h>
+
 #include <string.h>
 #include <time.h>
 #include <stdio.h>
@@ -37,7 +38,6 @@
 #include "ipx.h"
 #include "ipxserver.h"
 #include "timer.h"
-#include "SDL_net.h"
 #include "programs.h"
 #include "pic.h"
 

src/hardware/mixer.cpp

@@ -38,7 +38,8 @@
 #include <mmsystem.h>
 #endif
 
-#include "SDL.h"
+#include <SDL.h>
+
 #include "mem.h"
 #include "pic.h"
 #include "dosbox.h"

src/hardware/serialport/misc_util.h

@@ -16,7 +16,6 @@
  *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
  */
 
-
 #ifndef SDLNETWRAPPER_H
 #define SDLNETWRAPPER_H
 
@@ -58,13 +57,10 @@
  #define CAPWORD NETWRAPPER_TCP
 #endif
 
-#include "SDL_net.h"
-
-
+#include <SDL_net.h>
 
 Bit32u Netwrapper_GetCapabilities();
 
-
 class TCPClientSocket {
 	public:
 	TCPClientSocket(TCPsocket source);