Added fallback values for compilers/stdlibs that don't recognize SIGWINCH or IUTF8

nne.c

@@ -30,6 +30,13 @@
 #define NNE_TABWIDTH 2
 #endif
 #define NNE_PAGESIZE 2048 /* memory page size in bytes for main text buffer */
+/* non-POSIX fallbacks for some flags */
+#ifndef SIGWINCH 
+#define SIGWINCH 28
+#endif
+#ifndef IUTF8
+#define IUTF8 0x4000
+#endif
 
 /* terminal control macros (constants) */
 #define ERESET "\x1b[0m"      /* reset the styling */