Gui: fix image handling:

* Change FileHandlder to accepts all image format supported by Qt
* Make sure image object is not touched after accepting or rejecting changes
* Make option 'Keep aspect ratio' the default
* Fix WhatThis text of command

src/Gui/CommandView.cpp

@@ -1982,7 +1982,7 @@ StdViewLoadImage::StdViewLoadImage()
     sGroup      = "Standard-View";
     sMenuText   = QT_TR_NOOP("Load image...");
     sToolTipText= QT_TR_NOOP("Loads a image");
-    sWhatsThis  = "Std_ViewLoadPicture";
+    sWhatsThis  = "Std_ViewLoadImage";
     sStatusTip  = QT_TR_NOOP("Loads a image");
     sPixmap     = "image-open";
     eType       = 0;

src/Gui/FileHandler.cpp

@@ -24,6 +24,7 @@
 #include "PreCompiled.h"
 #ifndef _PreComp_
 # include <QFileInfo>
+# include <QImageReader>
 # include <QStringList>
 # include <Inventor/SoInput.h>
 #endif
@@ -146,10 +147,14 @@ bool FileHandler::openInternal()
         return true;
     }
 
-    if (hasExtension(QStringList() << QLatin1String("bmp")
-                                   << QLatin1String("jpg")
-                                   << QLatin1String("png")
-                                   << QLatin1String("xpm"))) {
+    QStringList supportedFormats;
+    auto imageFormats = QImageReader::supportedImageFormats();
+    std::transform(imageFormats.cbegin(), imageFormats.cend(),
+                   std::back_inserter(supportedFormats), [](const QByteArray& format) {
+        return QString::fromLatin1(format);
+    });
+
+    if (hasExtension(supportedFormats)) {
         openImage();
         return true;
     }

src/Gui/TaskView/TaskImageScale.ui

@@ -69,6 +69,9 @@
         <property name="text">
          <string>Keep aspect ratio</string>
         </property>
+        <property name="checked">
+         <bool>true</bool>
+        </property>
        </widget>
       </item>
      </layout>

src/Gui/TaskView/TaskOrientation.cpp

@@ -72,6 +72,7 @@ void TaskOrientation::accept()
     if (!feature.expired()) {
         App::Document* doc = feature->getDocument();
         doc->commitTransaction();
+        doc->recompute();
     }
 }
 
@@ -80,6 +81,7 @@ void TaskOrientation::reject()
     if (!feature.expired()) {
         App::Document* doc = feature->getDocument();
         doc->abortTransaction();
+        feature->purgeTouched();
     }
 }