* Rename QML modules as such, creating the proper transitional packages and
  renaming the necessary files:
  - qtdeclarative5-dialogs-plugin → qml-module-qtquick-dialogs.
  - qtdeclarative5-folderlistmodel-plugin →
    qml-module-qt-labs-folderlistmodel.
  - qtdeclarative5-localstorage-plugin → qml-module-qtquick-localstorage.
  - qtdeclarative5-models-plugin → qml-model-qtqml-models2.
  - qtdeclarative5-particles-plugin → qml-module-qtquick-particles2.
  - qtdeclarative5-privatewidgets-plugin →
    qml-module-qtquick-privatewidgets.
  - qtdeclarative5-qtquick2-plugin → qml-module-qtquick2.
  - qtdeclarative5-settings-plugin → qml-module-qt-labs-settings.
  - qtdeclarative5-test-plugin → qml-module-qttest.
  - qtdeclarative5-window-plugin → qml-module-qtquick-window2.
  - qtdeclarative5-xmllistmodel-plugin → qml-module-qtquick-xmllistmodel.
* Override lintian for duplicated long description on transitional packages.
* Add qml-module-qtquick2 as qml-module-qttest dependency.
* Update symbols files with buildd's logs.