Debugger: Export DebuggerManager and DebuggerStartParameters.

For device debugging. Move both from namespace
Debugger::Internal to Debugger, export them, give
DebuggerManager a static instance().

src/plugins/debugger/debuggerrunner.h

@@ -40,9 +40,9 @@ class LocalApplicationRunConfiguration;
 }
 
 namespace Debugger {
-namespace Internal {
-
 class DebuggerManager;
+
+namespace Internal {
 class StartData;
 
 typedef QSharedPointer<ProjectExplorer::RunConfiguration>