STYLE: Simplify top level cmakelists

ENH: Report which Databases/SQL or Video examples are not built

ENH: Update minimum required version of CMake from 2.8.8 to 3.3

COMP: Fix configure error when build against Qt4

module.cmake: Update list based on output of WhatModulesVTK.py

COMP: Fix VisualizationAlgorithms/PlateVibration build on case sensitive system

The module has the "Legacy" prefix anticipating a module named
WikiModuleConfig will be added.

Note that testing for VTK_BINARY_DIR or Module_WikiExamples are equivalent
since both evaluate to True when building the module from within VTK.

Report message are like the following:

```
-- VTKWikiExamples: Building VTKWikiExamples stand-alone
-- VTKWikiExamples: Building VTKWikiExamples stand-alone - yes
-- VTKWikiExamples: Setting executables prefix
-- VTKWikiExamples: Setting executables prefix - no
-- VTKWikiExamples: VTK VERSION: 8.1.0(OpenGL2)
[...]
```

or

```
[...]
-- VTKWikiExamples: Building VTKWikiExamples stand-alone
-- VTKWikiExamples: Building VTKWikiExamples stand-alone - no
-- VTKWikiExamples: Setting executables prefix
-- VTKWikiExamples: Setting executables prefix - yes [prefix: wiki]
[...]
```

The version now match the one used in VTK 8.1

This commit fixes the following error:

```
[...]
-- Found Qt4: /home/jcfr/Support/qt-everywhere-opensource-build-4.8.7/bin/qmake (found version "4.8.7")
CMake Error at src/Cxx/Qt/CMakeLists.txt:64 (TARGET_LINK_LIBRARIES):
  Cannot specify link libraries for target "BorderWidgetQt" which is not
  built by this project.
[...]

The test label is already set in ExampleTesting CMake module.

Implementing Bill's changes from the C++ version.

Adding the DisplacementPlot example.

Adding PlateVibration.

Fixing Spring.cxx, also adding classes used to Fig 6-12.