C++: Remove unneeded qualifications

Mostly done using the following ruby script:
Dir.glob('**/*.cpp').each { |file|
  next if file =~ %r{src/shared/qbs|/qmljs/}
  s = File.read(file)
  s.scan(/^using namespace (.*);$/) {
    ns = $1
    t = s.gsub(/^(.*)\b#{ns}::((?!Const)[A-Z])/) { |m|
      before = $1
      char = $2
      if before =~ /"|\/\/|\\|using|SIGNAL|SLOT|Q_/
        m
      else
        before + char
      end
    }
    if t != s
      puts file
      File.open(file, 'w').write(t)
    end
  }
}

Change-Id: I6fbe13ddc1485efe95c3156097bf41d90c0febac
Reviewed-by: Nikolai Kosjar <nikolai.kosjar@theqtcompany.com>

src/libs/cplusplus/LookupItem.cpp

@@ -38,7 +38,7 @@
 
 using namespace CPlusPlus;
 
-uint CPlusPlus::qHash(const CPlusPlus::LookupItem &key)
+uint CPlusPlus::qHash(const LookupItem &key)
 {
     const uint h1 = QT_PREPEND_NAMESPACE(qHash)(key.type().type());
     const uint h2 = QT_PREPEND_NAMESPACE(qHash)(key.scope());