Provide instance()-method for Utils::NetworkAccessManager.

Preemptively fix exit warning "QEventLoop cannot be used
without QApplication" (Qt 5/dev) emitted by destruction of
the of the generic highlighter manager singleton which had a
member of type Utils::NetworkAccessManager.

Use a single instance of Utils::NetworkAccessManager for the
main thread and clean up properly using a qAddPostRoutine().

Change-Id: Ida57b9028a79eb4927818ce49088ea567f3bdfd6
Reviewed-by: hjk <hjk121@nokiamail.com>
Reviewed-by: Peter Hartmann <phartmann@blackberry.com>
Reviewed-by: Eike Ziller <eike.ziller@digia.com>

src/plugins/git/gitorious/gitorious.cpp

@@ -357,11 +357,6 @@ void GitoriousProjectReader::readUnknownElement(QXmlStreamReader &reader)
 
 // --- Gitorious
 
-Gitorious::Gitorious() :
-    m_networkManager(0)
-{
-}
-
 Gitorious &Gitorious::instance()
 {
     static Gitorious gitorious;
@@ -523,9 +518,7 @@ void Gitorious::slotReplyFinished()
 // dispatch. Use host name in case an entry is removed in-between
 QNetworkReply *Gitorious::createRequest(const QUrl &url, int protocol, int hostIndex, int page)
 {
-    if (!m_networkManager)
-        m_networkManager = new Utils::NetworkAccessManager(this);
-    QNetworkReply *reply = m_networkManager->get(QNetworkRequest(url));
+    QNetworkReply *reply = Utils::NetworkAccessManager::instance()->get(QNetworkRequest(url));
     connect(reply, SIGNAL(finished()), this, SLOT(slotReplyFinished()));
     reply->setProperty(protocolPropertyC, QVariant(protocol));
     reply->setProperty(hostNamePropertyC, QVariant(hostName(hostIndex)));

src/plugins/git/gitorious/gitorious.h

@@ -36,7 +36,6 @@
 #include <QObject>
 
 QT_BEGIN_NAMESPACE
-class QNetworkAccessManager;
 class QNetworkReply;
 class QDebug;
 class QUrl;
@@ -159,7 +158,7 @@ private slots:
     void slotReplyFinished();
 
 private:
-    Gitorious();
+    Gitorious() {}
     void listProjectsReply(int hostIndex, int page, const QByteArray &data);
     void listCategoriesReply(int index, QByteArray data);
     void emitError(const QString &e);
@@ -167,7 +166,6 @@ private:
     void startProjectsRequest(int index, int page = 1);
 
     QList<GitoriousHost> m_hosts;
-    QNetworkAccessManager *m_networkManager;
 };
 
 } // namespace Internal