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/test/paymentservertests.cpp

@@ -1,17 +1,17 @@
-#include <QCoreApplication>
-#include <QDebug>
-#include <QTemporaryFile>
-#include <QVariant>
-#include <QFileOpenEvent>
+#include "paymentservertests.h"
+
+#include "optionsmodel.h"
+#include "paymentrequestdata.h"
+
+#include "util.h"
 
 #include <openssl/x509.h>
 #include <openssl/x509_vfy.h>
-
-#include "optionsmodel.h"
-#include "paymentservertests.h"
-#include "paymentrequestdata.h"
-#include "util.h"
-
+#include <QCoreApplication>
+#include <QDebug>
+#include <QFileOpenEvent>
+#include <QTemporaryFile>
+#include <QVariant>
 
 
 X509 *parse_b64der_cert(const char* cert_data)

src/qt/test/paymentservertests.h

@@ -1,11 +1,11 @@
 #ifndef PAYMENTSERVERTESTS_H
 #define PAYMENTSERVERTESTS_H
 
-#include <QTest>
-#include <QObject>
-
 #include "../paymentserver.h"
 
+#include <QObject>
+#include <QTest>
+
 class PaymentServerTests : public QObject
 {
     Q_OBJECT

src/qt/test/test_main.cpp

@@ -1,8 +1,10 @@
-#include <QTest>
-#include <QObject>
 
-#include "uritests.h"
+
 #include "paymentservertests.h"
+#include "uritests.h"
+
+#include <QObject>
+#include <QTest>
 
 // This is all you need to run all the tests
 int main(int argc, char *argv[])

src/qt/test/uritests.cpp

@@ -1,6 +1,7 @@
 #include "uritests.h"
-#include "../guiutil.h"
-#include "../walletmodel.h"
+
+#include "guiutil.h"
+#include "walletmodel.h"
 
 #include <QUrl>
 

src/qt/test/uritests.h

@@ -1,8 +1,8 @@
 #ifndef URITESTS_H
 #define URITESTS_H
 
-#include <QTest>
 #include <QObject>
+#include <QTest>
 
 class URITests : public QObject
 {