Fix various qdoc-warnings.

qtbase/src/corelib/doc/src/containers.qdoc:28: warning: Can't link to 'QList:end()'
qtbase/src/corelib/kernel/qmetaobject.cpp:2680: warning: Cannot find 'fromType(...)' in '\fn' QMetaEnum QMetaEnum::fromType() const
qtbase/src/corelib/kernel/qmetatype.cpp:1117: warning: Cannot find 'qMetaTypeTypeImpl(...)' in '\fn' int qMetaTypeTypeImpl(const char *typeName)
qtbase/src/corelib/plugin/qplugin.qdoc:48: warning: Cannot find file to quote from: 'plugins/interfaces.h'

Change-Id: Ie613253211e16ec616ccb70c24c625a9d5352d1b
Reviewed-by: Olivier Goffart (Woboq GmbH) <ogoffart@woboq.com>

src/corelib/doc/src/containers.qdoc

@@ -465,7 +465,7 @@
     imaginary item one position past the last item in the container.
     \l {QList::end()}{end()} marks an invalid position; it must never be dereferenced.
     It is typically used in a loop's break condition. If the list is
-    empty, \l{QList::begin}{begin()} equals \l{QList:end()}{end()}, so we never execute the loop.
+    empty, \l{QList::begin}{begin()} equals \l{QList::end()}{end()}, so we never execute the loop.
 
     The diagram below shows the valid iterator positions as red
     arrows for a vector containing four items:

src/corelib/kernel/qmetaobject.cpp

@@ -2678,7 +2678,7 @@ QByteArray QMetaEnum::valueToKeys(int value) const
 }
 
 /*!
-    \fn QMetaEnum QMetaEnum::fromType() const
+    \fn QMetaEnum QMetaEnum::fromType()
     \since 5.5
 
     Returns the QMetaEnum corresponding to the type in the template parameter.

src/corelib/kernel/qmetatype.cpp

@@ -1117,7 +1117,7 @@ bool QMetaType::isRegistered(int type)
 }
 
 /*!
-    \fn int qMetaTypeTypeImpl(const char *typeName)
+    \fn int qMetaTypeTypeImpl(const char *typeName, int length)
     \internal
 
     Implementation of QMetaType::type().

src/corelib/plugin/qplugin.qdoc

@@ -44,7 +44,7 @@
     to the interface class called \a ClassName. The \a Identifier must
     be unique. For example:
 
-    \snippet plugins/interfaces.h 3
+    \snippet code/doc_src_qplugin.cpp 0
 
     This macro is normally used right after the class definition for
     \a ClassName, in a header file. See the

src/dbus/qdbusconnection.cpp

@@ -1110,7 +1110,7 @@ QDBusConnection QDBusConnection::systemBus()
   \deprecated
 
   Always returns a disconnected, invalid QDBusConnection object. For the old
-  functionality of determining the sender connection, please use \ref QDBusContext.
+  functionality of determining the sender connection, please use QDBusContext.
 
   \sa QDBusContext
 */