build: Add missing <cstring> includes for MinGW compatibility

src/loaders/svg/tvgSvgLoader.cpp

@@ -51,6 +51,7 @@
 
 #define _USE_MATH_DEFINES       //Math Constants are not defined in Standard C/C++.
 
+#include <cstring>
 #include <fstream>
 #include <float.h>
 #include <math.h>

src/loaders/svg/tvgSvgPath.cpp

@@ -50,6 +50,7 @@
 
 #define _USE_MATH_DEFINES       //Math Constants are not defined in Standard C/C++.
 
+#include <cstring>
 #include <math.h>
 #include <clocale>
 #include <ctype.h>

src/loaders/svg/tvgSvgSceneBuilder.cpp

@@ -49,6 +49,7 @@
 */
 
 
+#include <cstring>
 #include <string>
 #include "tvgMath.h"
 #include "tvgSvgLoaderCommon.h"

src/loaders/svg/tvgSvgUtil.cpp

@@ -20,6 +20,7 @@
  * SOFTWARE.
  */
 
+#include <cstring>
 #include <math.h>
 #include <memory.h>
 #include "tvgSvgUtil.h"

src/loaders/svg/tvgXmlParser.cpp

@@ -20,6 +20,7 @@
  * SOFTWARE.
  */
 
+#include <cstring>
 #include <ctype.h>
 #include <string>
 

src/savers/tvg/tvgTvgSaver.cpp

@@ -24,6 +24,8 @@
 #include "tvgTvgSaver.h"
 #include "tvgLzw.h"
 
+#include <cstring>
+
 #ifdef _WIN32
     #include <malloc.h>
 #else