Update to latest version of qtsingleapplication for Qt5 support

Signed-off-by: Taylor Braun-Jones <taylor.braun-jones@ge.com>
Added qtsingleapplication customizations again on top of updated files.
Use Qt5 QTemporaryDir class instead of custom Qt4 code.
Merge branch 'bug-17529-Upgrade-qtsingleapplication'

* bug-17529-Upgrade-qtsingleapplication:
  Use Qt5 QTemporaryDir class instead of custom Qt4 code.
  Added qtsingleapplication customizations again on top of updated files.
  Update to latest version of qtsingleapplication for Qt5 support
Merge branch 'bug-18079-fix-qt5-build-due-to-use-of-deprecated-Geometry2DData'

* bug-18079-fix-qt5-build-due-to-use-of-deprecated-Geometry2DData:
  COMP: Fix QmlMitkRenderWindowItem using deprecated Geometry2DDataMapper2D
COMP: Correct Windows type conversions for strings.
Merge branch 'bug-17529-Upgrade-qtsingleapplication'

* bug-17529-Upgrade-qtsingleapplication:
  COMP: Correct Windows type conversions for strings.
Merge branch 'bug-16674-fix-memory-leaks-ImageReadAccessor'

* bug-16674-fix-memory-leaks-ImageReadAccessor:
  Fix memory leak when creating a ImageReadAccessor with IgnoreLock enabled
  Fix memory leak when image accessor fails to construct
Merge branch 'bug-16674-fix-memory-leaks-VTK_DEBUG_LEAKS'

* bug-16674-fix-memory-leaks-VTK_DEBUG_LEAKS:
  Fix leaks found by running non-rendering unit tests with VTK_DEBUG_LEAKS
Fix installation of CTK Qt plugins.
Merge branch 'bug-18064-ctk-qt-plugin-installation-broken'

* bug-18064-ctk-qt-plugin-installation-broken:
  Fix installation of CTK Qt plugins.
Fix VTK memory leaks in SurfaceToImageFilter

... due to invalid vtkSmartPointer usage.

Signed-off-by: Taylor Braun-Jones <taylor.braun-jones@ge.com>
Removed deprecated MitkExt module.
Removed redundant and unused data files. Using http links for tutorial data.
Merge branch 'bug-18081-remove-mitkext-module'

* bug-18081-remove-mitkext-module:
  Removed redundant and unused data files. Using http links for tutorial data.
  Removed deprecated MitkExt module.
add delay after render, so the screenshot is only made when the scene is rendered completely
Fix memory leak in mitkImageVtkMapper2DLevelWindow unit test

Signed-off-by: Taylor Braun-Jones <taylor.braun-jones@ge.com>
Fix memory leaks in VtkPropRenderer::Initialize2DvtkCamera

Signed-off-by: Taylor Braun-Jones <taylor.braun-jones@ge.com>
Merge branch 'bug-18017-RestructurePlaneGeometryTest'
replace delay by forceImmediateUpdate