Some of the test data sets are derived from data sets that are commonly
distributed to test visualization algorithms and are featured in
numerous papers. However, I am unable to track down the original source
let alone identify what license, if any, they were released under. To
avoid any complications with data ownership, remove these data sets and
replace them with in house data sets that we explicitly own.
This mechanism sets up CMake variables that allow a user to select which
modules/libraries to create. Dependencies will be tracked down to ensure
that all of a module's dependencies are also enabled.
The modules are also arranged into groups.
Groups allow you to set the enable flag for a group of modules at once.
Thus, if you have several modules that are likely to be used together,
you can create a group for them.
This can be handy in converting user-friendly CMake options (such as
`VTKm_ENABLE_RENDERING`) to the modules that enable that by pointing to
the appropriate group.
