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/model/StackTrace.h

@@ -0,0 +1,32 @@
+/*
+ * Copyright 2009, Ingo Weinhold, [email protected].
+ * Distributed under the terms of the MIT License.
+ */
+#ifndef STACK_TRACE_H
+#define STACK_TRACE_H
+
+#include <ObjectList.h>
+
+#include "StackFrame.h"
+
+
+class StackTrace : public BReferenceable {
+public:
+								StackTrace();
+	virtual						~StackTrace();
+
+			bool				AddFrame(StackFrame* frame);
+									// takes over reference (also on error)
+
+			int32				CountFrames() const;
+			StackFrame*			FrameAt(int32 index) const;
+
+private:
+			typedef BObjectList<StackFrame> StackFrameList;
+
+private:
+			StackFrameList		fStackFrames;
+};
+
+
+#endif	// STACK_TRACE_H