debugger: The DebuggerEngine refactoring.

This replaces the (de facto) singleton engines and data handlers by classes
that are instantiated per run. The DebuggerRunControl will now create an
object of (a class derived from) DebuggerEngine that contains all the relevant
"dynamic" data.

DebuggerManager is no more. The "singleton" bits are merged into DebuggerPlugin,
whereas the data bits went to DebuggerEngine.

There is no formal notion of a "current" DebuggerEngine. However, as there's
only one DebuggerEngine at a time that has its data models connected to the
view, there's still some "de facto" notion of a "current" engine. Calling
SomeModel::setData(int role, QVariant data) with custom role is used as the
primary dispatch mechanism from the views to the "current" data models
(and the engine, as all data models know their engine).

src/plugins/debugger/gdb/trkgdbadapter.cpp

@@ -1724,7 +1724,8 @@ bool TrkGdbAdapter::initializeDevice(const QString &remoteChannel, QString *erro
         return false;
     }
     // Run config: Acquire from device manager.
-    m_trkDevice = SymbianUtils::SymbianDeviceManager::instance()->acquireDevice(remoteChannel);
+    m_trkDevice = SymbianUtils::SymbianDeviceManager::instance()
+        ->acquireDevice(remoteChannel);
     if (m_trkDevice.isNull()) {
         *errorMessage = tr("Unable to acquire a device on '%1'. It appears to be in use.").arg(remoteChannel);
         return false;
@@ -2140,7 +2141,7 @@ void TrkGdbAdapter::trkReloadRegisters()
 {
     // Take advantage of direct access to cached register values.
     QTC_ASSERT(m_snapshot.registerValid, /**/);
-    RegisterHandler *handler = m_engine->runControl()->registerHandler();
+    RegisterHandler *handler = m_engine->registerHandler();
     Registers registers = handler->registers();
 
     QTC_ASSERT(registers.size() >= 26,
@@ -2164,12 +2165,10 @@ void TrkGdbAdapter::trkReloadThreads()
 {
     // Take advantage of direct access to cached register values.
     QTC_ASSERT(m_snapshot.registerValid, /**/);
-    QList<ThreadData> threads;
-    foreach (const Session::Thread &thread, m_session.threads) {
+    Threads threads;
+    foreach (const Session::Thread &thread, m_session.threads)
         threads.append(thread);
-    }
-    ThreadsHandler *handler = m_engine->manager()->threadsHandler();
-    handler->setThreads(threads);
+    m_engine->threadsHandler()->setThreads(threads);
 }
 
 } // namespace Internal