Fix possible missing NUL at end of string

There are were a few uses of 'strncpy' that could lead to a missing NUL,
resulting in possible garbage being displayed. As suggested by Tamas,
use 'wstrlcpy' instead

WINGs/wcolorpanel.c

@@ -3400,9 +3400,8 @@ char *generateNewFilename(char *curName)
 
 	newName = wmalloc(baseLen + 16);
 	strncpy(newName, curName, baseLen);
-	newName[baseLen] = 0;
 
-	sprintf(&newName[baseLen], " {%i}", n + 1);
+	snprintf(&newName[baseLen], 16, " {%i}", n + 1);
 
 	return newName;
 }