Debugger: Split into core library and application.

- Add subfolder src/kits/debugger which contains the debugger's core
  functionality and lower layers. Correspondingly add headers/private/debugger
  for shared headers to be used by clients such as the Debugger application
  and eventual remote_debug_server. Adjust various files to account for
  differences as a result of the split and moves.
- Add libdebugger.so to minimal Jamfile.

headers/private/debugger/ids/ObjectID.h

@@ -0,0 +1,46 @@
+/*
+ * Copyright 2009, Ingo Weinhold, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef OBJECT_ID_H
+#define OBJECT_ID_H
+
+
+#include <Referenceable.h>
+
+
+class ObjectID : public BReferenceable {
+public:
+								ObjectID();
+	virtual						~ObjectID();
+
+	inline	uint32				HashValue() const;
+
+	virtual	bool				operator==(const ObjectID& other) const = 0;
+	inline	bool				operator!=(const ObjectID& other) const;
+
+protected:
+	virtual	uint32				ComputeHashValue() const = 0;
+
+protected:
+	mutable	uint32				fHashValue;
+};
+
+
+uint32
+ObjectID::HashValue() const
+{
+	if (fHashValue == 0)
+		fHashValue = ComputeHashValue();
+	return fHashValue;
+}
+
+
+bool
+ObjectID::operator!=(const ObjectID& other) const
+{
+	return !(*this == other);
+}
+
+
+#endif	// OBJECT_ID_H