debugger: start 'runcontrol-ification' of the debugger plugin.

This replaces most uses of DebuggerStartParameters by DebuggerRunControl
which is a simple RunControl with a DebuggerStartParameters member.

Plan is to move all global state to the run controls, and possibly
introduce specialized ones for core debugging etc.

src/plugins/debugger/script/scriptengine.h

@@ -71,7 +71,7 @@ private:
     void shutdown();
     void setToolTipExpression(const QPoint &mousePos,
         TextEditor::ITextEditor *editor, int cursorPos);
-    void startDebugger(const DebuggerStartParametersPtr &sp);
+    void startDebugger(const DebuggerRunControl *runControl);
 
     void exitDebugger();