Assorted clean up and small fixes

Created by: germasch

Here's a bunch of little things I've had lie around for a while now. These are mostly independent from reach other, so pieces could be dropped if needed.

It's mostly some cleanup following from the stdint type changes. Maybe the most noteworthy change is moving the ADIOS2_FOREACH_*_TYPE_1ARG macros into the CXX11 bindings, as all of the rest of the code now uses he _STDTYPE_ macros, so having the _TYPE_ macro out of the way should prevent any confusion.