They now grab the global runtime device tracker. In some cases, I've
added the ability to set/get the tracker to change it from the global.
In others I just removed the local copy, since it was just hooked into
the global tracker.
Change the VTKM_CONT_EXPORT to VTKM_CONT. (Likewise for EXEC and
EXEC_CONT.) Remove the inline from these macros so that they can be
applied to everything, including implementations in a library.
Because inline is not declared in these modifies, you have to add the
keyword to functions and methods where the implementation is not inlined
in the class.
The base classes for all the filters are named with 'Filter' at the end.
Generally the convention in VTK-m is to place the most general
descriptor (in this case Filter) first, which makes it easier to find
items in ordered lists.
This commit resolves issue #59.
