Debugger: Improve configuration error reporting.

- Make showWarningWithOptions actually show the details.
- Show errors from multiple engines as separate messages.
- Remove 'enabled' option from CDB (handled by toolchain config now).
- Show ABI as tooltip in debbugger toolchain chooser.

src/plugins/debugger/debuggerrunner.h

@@ -42,6 +42,7 @@
 
 #include <QtCore/QScopedPointer>
 #include <QtCore/QPair>
+#include <QtCore/QStringList>
 
 namespace Utils {
 class Environment;
@@ -63,8 +64,10 @@ class DEBUGGER_EXPORT ConfigurationCheck
 public:
     ConfigurationCheck();
     operator bool() const;
+    QString errorDetailsString() const;
 
     QString errorMessage;
+    QStringList errorDetails;
     QString settingsCategory;
     QString settingsPage;
     QPair<DebuggerEngineType, DebuggerEngineType> masterSlaveEngineTypes;