Initial import of Red Planet v4.10 Win32 source

Imports the current Win32 source for the pod-racing game 'Red Planet',
built on the MUNGA engine and its L4 (Win32/DirectX) platform layer:

- MUNGA / MUNGA_L4: cross-platform engine core and Win32 backend
- RP / RP_L4: Red Planet game logic and Win32 application
- DivLoader, Setup1: asset loader and installer project
- lib, MUNGA_L4/openal, MUNGA_L4/sos: third-party audio dependencies

Removed stale Subversion metadata and added .gitignore/.gitattributes.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

MUNGA/UNITVEC.cpp

@@ -0,0 +1,36 @@
+#include "munga.h"
+#pragma hdrstop
+
+#include "unitvec.h"
+
+UnitVector& UnitVector::Lerp(const UnitVector& /*v1*/, const UnitVector& /*v2*/, Scalar /*t*/)
+{
+	Check_Pointer(this);
+	Tell("UnitVector::Lerp stubbed out!\n");
+	return *this;
+}
+
+Logical UnitVector::TestInstance() const
+{
+	Scalar length = Vector3D::LengthSquared();
+	Scalar diff = 1.0f - length;
+	if (!Small_Enough(diff, 2e-5))
+	{
+		length = x*x + y*y + z*z;
+		diff = 1.0f - length;
+		if (!Small_Enough(diff, 2e-5))
+		{
+			Dump(*this);
+			Dump(length);
+			Dump(x*x + y*y + z*z);
+			Dump(diff);
+			return false;
+		}
+	}
+	return true;
+}
+
+#if defined(TEST_CLASS)
+	#include "unitvec.tcp"
+#endif
+