- add dllexport and fix some linker error for windows

- add includes
- fix gl function names (from no_ext to arb extension)
- rearrange includes, so that glew.h is included before gl.h (through qt5.0) is included
- add some missing file properties

git-svn-id: http://www.openflipper.org/svnrepo/OpenFlipper/branches/Free@19018 383ad7c9-94d9-4d36-a494-682f7c89f535

FileHeightFieldImage.cc

@@ -40,6 +40,8 @@
 *                                                                            *
 \*===========================================================================*/
 
+#include "FileHeightFieldImage.hh"
+#include "ImageDialog.hh"
 
 #if QT_VERSION >= 0x050000 
   #include <QtWidgets>
@@ -49,11 +51,7 @@
 
 #include <QFileInfo>
 #include <QSettings>
-
-#include "FileHeightFieldImage.hh"
-#include "ImageDialog.hh"
-
-#include "OpenFlipper/BasePlugin/PluginFunctions.hh"
+#include <OpenFlipper/BasePlugin/PluginFunctions.hh>
 
 void FileHeightFieldPNGPlugin::initializePlugin() {
 }