ToolChain: Update projectsmode on tool chain changes

Update the projects mode on tool chain changes.

Task-number: QTCREATORBUG-4431

src/plugins/projectexplorer/toolchainmanager.cpp

@@ -96,6 +96,12 @@ ToolChainManager::ToolChainManager(QObject *parent) :
     m_instance = this;
     connect(Core::ICore::instance(), SIGNAL(saveSettingsRequested()),
             this, SLOT(saveToolChains()));
+    connect(this, SIGNAL(toolChainAdded(ProjectExplorer::ToolChain*)),
+            this, SIGNAL(toolChainsChanged()));
+    connect(this, SIGNAL(toolChainRemoved(ProjectExplorer::ToolChain*)),
+            this, SIGNAL(toolChainsChanged()));
+    connect(this, SIGNAL(toolChainUpdated(ProjectExplorer::ToolChain*)),
+            this, SIGNAL(toolChainsChanged()));
 }
 
 void ToolChainManager::restoreToolChains()

src/plugins/projectexplorer/toolchainmanager.h

@@ -82,6 +82,8 @@ signals:
     void toolChainRemoved(ProjectExplorer::ToolChain *);
     // Tool chain was updated.
     void toolChainUpdated(ProjectExplorer::ToolChain *);
+    // Something changed:
+    void toolChainsChanged();
 
 private:
     explicit ToolChainManager(QObject *parent = 0);

src/plugins/qt4projectmanager/qt4projectconfigwidget.cpp

@@ -114,6 +114,9 @@ Qt4ProjectConfigWidget::Qt4ProjectConfigWidget(Qt4BaseTarget *target)
 
     connect(target->qt4Project(), SIGNAL(buildDirectoryInitialized()),
             this, SLOT(updateImportLabel()));
+
+    connect(ProjectExplorer::ToolChainManager::instance(), SIGNAL(toolChainsChanged()),
+            this, SLOT(updateToolChainCombo()));
 }
 
 Qt4ProjectConfigWidget::~Qt4ProjectConfigWidget()