Clean up single namespace forward-declarations

Done using the following ruby script:

Dir.glob('**/*.h').each { |file|
  if File.file?(file)
    s = File.read(file)
    t = s.gsub(/^namespace .+ \{\n\s*class .*;\n\s*\}.*$/) { |m| m.gsub(/\n\s*/, ' ').gsub(/\s*\/\/.*$/, '') }
    if t != s
      puts file
      File.open(file, 'w').write(t)
    end
  end
}

Change-Id: Iffcb966e90eb8e1a625eccd5dd0b94f000ae368e
Reviewed-by: hjk <hjk121@nokiamail.com>

src/plugins/qmlprojectmanager/fileformat/filefilteritems.h

@@ -38,9 +38,7 @@
 
 QT_FORWARD_DECLARE_CLASS(QDir)
 
-namespace Utils {
-class FileSystemWatcher;
-}
+namespace Utils { class FileSystemWatcher; }
 
 namespace QmlProjectManager {
 

src/plugins/qmlprojectmanager/qmlapplicationwizard.h

@@ -33,9 +33,7 @@
 #include <coreplugin/basefilewizard.h>
 #include <projectexplorer/baseprojectwizarddialog.h>
 
-namespace ExtensionSystem {
-class IPlugin;
-} // namespace ExtensionSystem
+namespace ExtensionSystem { class IPlugin; }
 
 namespace QmlProjectManager {
 namespace Internal {

src/plugins/qmlprojectmanager/qmlprojectnodes.h

@@ -35,9 +35,7 @@
 #include <QStringList>
 #include <QHash>
 
-namespace Core {
-class IDocument;
-}
+namespace Core { class IDocument; }
 
 namespace QmlProjectManager {
 

src/plugins/qmlprojectmanager/qmlprojectrunconfiguration.h

@@ -38,9 +38,7 @@
 
 QT_FORWARD_DECLARE_CLASS(QStringListModel)
 
-namespace Core {
-    class IEditor;
-}
+namespace Core { class IEditor; }
 
 namespace QtSupport { class BaseQtVersion; }