Reduce warnings for yaml-cpp

- Use only utils/YamlUtils.h to pull in yaml-cpp and supporting code.
 - When compiling with clang, turn off warnings that the system header
   for yaml-cpp would generate.

src/libcalamares/Settings.cpp

@@ -27,8 +27,6 @@
 #include <QFile>
 #include <QPair>
 
-#include <yaml-cpp/yaml.h>
-
 static bool
 hasValue( const YAML::Node& v )
 {

src/libcalamares/utils/YamlUtils.cpp

@@ -20,8 +20,6 @@
 
 #include "utils/Logger.h"
 
-#include <yaml-cpp/yaml.h>
-
 #include <QByteArray>
 #include <QFile>
 #include <QFileInfo>

src/libcalamares/utils/YamlUtils.h

@@ -26,11 +26,21 @@
 class QByteArray;
 class QFileInfo;
 
-namespace YAML
-{
-class Node;
-class Exception;
-}
+// The yaml-cpp headers are not C++11 warning-proof, especially
+// with picky compilers like Clang 8. Since we use Clang for the
+// find-all-the-warnings case, switch those warnings off for
+// the we-can't-change-them system headers.
+#ifdef __clang__
+#pragma clang diagnostic push
+#pragma clang diagnostic ignored "-Wzero-as-null-pointer-constant"
+#pragma clang diagnostic ignored "-Wshadow"
+#endif
+
+#include <yaml-cpp/yaml.h>
+
+#ifdef __clang__
+#pragma clang diagnostic pop
+#endif
 
 /// @brief Appends all te elements of @p node to the string list @p v
 void operator>>( const YAML::Node& node, QStringList& v );

src/libcalamaresui/Branding.cpp

@@ -32,9 +32,6 @@
 #include <QPixmap>
 #include <QVariantMap>
 
-#include <yaml-cpp/yaml.h>
-
-
 namespace Calamares
 {
 

src/libcalamaresui/modulesystem/Module.cpp

@@ -36,8 +36,6 @@
 #include "PythonQtViewModule.h"
 #endif
 
-#include <yaml-cpp/yaml.h>
-
 #include <QDir>
 #include <QFile>
 #include <QFileInfo>

src/libcalamaresui/modulesystem/ModuleManager.cpp

@@ -28,8 +28,6 @@
 #include "utils/Logger.h"
 #include "utils/YamlUtils.h"
 
-#include <yaml-cpp/yaml.h>
-
 #include <QApplication>
 #include <QDir>
 #include <QTimer>

src/modules/contextualprocess/Tests.cpp

@@ -22,8 +22,6 @@
 #include "utils/CommandList.h"
 #include "utils/YamlUtils.h"
 
-#include <yaml-cpp/yaml.h>
-
 #include <QtTest/QtTest>
 
 #include <QFileInfo>

src/modules/fsresizer/Tests.cpp

@@ -25,8 +25,6 @@
 #include "utils/Logger.h"
 #include "utils/YamlUtils.h"
 
-#include <yaml-cpp/yaml.h>
-
 #include <QtTest/QtTest>
 
 #include <QFileInfo>

src/modules/locale/GeoIPJSON.cpp

@@ -25,8 +25,6 @@
 
 #include <QByteArray>
 
-#include <yaml-cpp/yaml.h>
-
 GeoIPJSON::GeoIPJSON(const QString& attribute)
     : GeoIP( attribute.isEmpty() ? QStringLiteral( "time_zone" ) : attribute )
 {

src/modules/locale/LocaleViewStep.cpp

@@ -42,8 +42,6 @@
 #include <QNetworkReply>
 #include <QtConcurrent/QtConcurrentRun>
 
-#include <yaml-cpp/yaml.h>
-
 
 CALAMARES_PLUGIN_FACTORY_DEFINITION( LocaleViewStepFactory, registerPlugin<LocaleViewStep>(); )
 

src/modules/netinstall/NetInstallPage.cpp

@@ -36,8 +36,6 @@
 
 #include <QHeaderView>
 
-#include <yaml-cpp/yaml.h>
-
 using CalamaresUtils::yamlToVariant;
 
 NetInstallPage::NetInstallPage( QWidget* parent )

src/modules/netinstall/PackageModel.h

@@ -27,7 +27,10 @@
 #include <QObject>
 #include <QString>
 
-#include <yaml-cpp/yaml.h>
+namespace YAML
+{
+    class Node;
+}
 
 class PackageModel : public QAbstractItemModel
 {

src/modules/shellprocess/Tests.cpp

@@ -26,8 +26,6 @@
 #include "utils/Logger.h"
 #include "utils/YamlUtils.h"
 
-#include <yaml-cpp/yaml.h>
-
 #include <QtTest/QtTest>
 
 #include <QFileInfo>

src/modules/test_conf.cpp

@@ -21,13 +21,13 @@
  * shipped with each module for correctness -- well, for parseability.
  */
 
+#include "utils/YamlUtils.h"
+
 #include <unistd.h>
 #include <stdlib.h>
 
 #include <iostream>
 
-#include <yaml-cpp/yaml.h>
-
 #include <QFile>
 #include <QByteArray>