Fix to test to see if include paths actually exist.

RLN will now yell at you if you give it an include path that doesn't
exist.  Thanks to ggn for the idea!  :-)

rln.c

@@ -3115,6 +3115,21 @@ int main(int argc, char * argv[])
 		ExitLinker();
 	}
 
+	// Check to see if include paths actually exist
+	if (strlen(libdir) > 0)
+	{
+		DIR * test = opendir(libdir);
+
+		if (test == NULL)
+		{
+			printf("Invalid include path: %s\n", libdir);
+			errflag = 1;
+			ExitLinker();
+		}
+
+		closedir(test);
+	}
+
 	if (!zflag && !vflag)
 	{
 		ShowVersion();				// Display version information

rln.h

@@ -44,7 +44,7 @@
 
 #define MAJOR   1			// Major version number
 #define MINOR   6			// Minor version number
-#define PATCH   2			// Patch release number
+#define PATCH   3			// Patch release number
 
 #ifdef WIN32
 #define PLATFORM     "Win32"		// Release platform - Windows
@@ -81,6 +81,7 @@
 // Rather than rely on dodgy compilers for something that's now a C99 standard,
 // let's do this:
 #include <stdint.h>
+#include <dirent.h>
 
 struct OHEADER
 {