In preparation for supporting base types with more widths, add typedefs
for the base types with explicit widths (number of bits).
Also added a IdComponent type that should be used for indices for
components into tuples and vectors. There now should be no reason to use
"int" inside of VTK-m code (especially for indexing). This change cleans
up many of the int types that were used throughout.
We made this change a while ago to help with completion in IDEs.
(Completion was matching a bunch of wrapper macros that were almost
never used anywhere.) Most of the changes are in comments, but there are
a few bad macro definitions.
