(svn r4074) -Feature: [Makefile] the makefile can now detect if iconv is present in the system

if detected, WITH_ICONV will be defined in the C code
	WITH_ICONV is also added to Makefile.config
	OSX do not use this flag setting in Makefile.config, as it is set at compile time based on target OS version
	the actual C code is not changed as the current iconv code is hardcoded for OSX and would break if any other OS got iconv
	This detection system is by request of Darkvater

makefiledir/iconv_detector.c

@@ -0,0 +1,18 @@
+/* $Id$ */
+
+#include <stdlib.h>
+#include <iconv.h>
+#include <stdio.h>
+
+/* this is a pretty simple app, that will return 1 if it manages to compile and execute
+ * This means that it can be used by the makefile to detect if iconv is present on the current system
+ * no iconv means this file fails and will return nothing */
+
+int main ()
+{
+	iconv_t cd = iconv_open("","");
+	iconv(cd,NULL,NULL,NULL,NULL);
+	iconv_close(cd);
+	printf("1\n");
+	return 0;
+}