Cleanup code using forward declarations.

Use misc methods of avoiding unnecesary header includes.
Replace int typedefs with int##_t from stdint.h.
Replace PRI64[xdu] with PRI[xdu]64 from inttypes.h.
Normalize QT_VERSION ifs where possible.
Resolve some indirect dependencies as direct ones.
Remove extern declarations from .cpp files.

src/qt/addressbookpage.cpp

@@ -11,14 +11,14 @@
 
 #include "addresstablemodel.h"
 #include "bitcoingui.h"
-#include "editaddressdialog.h"
 #include "csvmodelwriter.h"
+#include "editaddressdialog.h"
 #include "guiutil.h"
 
-#include <QSortFilterProxyModel>
-#include <QClipboard>
-#include <QMessageBox>
+#include <QIcon>
 #include <QMenu>
+#include <QMessageBox>
+#include <QSortFilterProxyModel>
 
 AddressBookPage::AddressBookPage(Mode mode, Tabs tab, QWidget *parent) :
     QDialog(parent),