Add export macros to classes and fix warning

src/core/composer/qgscomposerframe.cpp

@@ -57,6 +57,9 @@ bool QgsComposerFrame::readXML( const QDomElement& itemElem, const QDomDocument&
 
 void QgsComposerFrame::paint( QPainter* painter, const QStyleOptionGraphicsItem* itemStyle, QWidget* pWidget )
 {
+  Q_UNUSED( itemStyle );
+  Q_UNUSED( pWidget );
+
   if ( !painter )
   {
     return;

src/core/composer/qgscomposerframe.h

@@ -22,7 +22,7 @@ class QgsComposition;
 class QgsComposerMultiFrame;
 
 /**Frame for html, table, text which can be divided onto several frames*/
-class QgsComposerFrame: public QgsComposerItem
+class CORE_EXPORT QgsComposerFrame: public QgsComposerItem
 {
   public:
     QgsComposerFrame( QgsComposition* c, QgsComposerMultiFrame* mf, qreal x, qreal y, qreal width, qreal height );

src/core/composer/qgscomposerhtml.h

@@ -21,7 +21,7 @@
 
 class QWebPage;
 
-class QgsComposerHtml: public QgsComposerMultiFrame
+class CORE_EXPORT QgsComposerHtml: public QgsComposerMultiFrame
 {
     Q_OBJECT
   public:

src/core/composer/qgscomposermultiframe.h

@@ -28,7 +28,7 @@ class QRectF;
 class QPainter;
 
 /**Abstract base class for composer entries with the ability to distribute the content to several frames (items)*/
-class QgsComposerMultiFrame: public QObject
+class CORE_EXPORT QgsComposerMultiFrame: public QObject
 {
     Q_OBJECT
   public:

src/core/composer/qgscomposermultiframecommand.h

@@ -23,7 +23,7 @@
 
 class QgsComposerMultiFrame;
 
-class QgsComposerMultiFrameCommand: public QUndoCommand
+class CORE_EXPORT QgsComposerMultiFrameCommand: public QUndoCommand
 {
   public:
     QgsComposerMultiFrameCommand( QgsComposerMultiFrame* multiFrame, const QString& text, QUndoCommand* parent = 0 );