Continue refactoring IO, ADIOS classes

Getting and defining available Variables at Open
Storing Variable position in Metadata, added to VariableBase
mpidummy: Added support for MPI_Reduce, MPI_Gatherv
Added utils and BPLS

Refactored IO, Variable class due to common functionality

Python bindings running but not printing values with bpls. Min and Max
captured correctly.

IO SetParameters and AddTransport will accept vector and map

Variable.cpp and Variable.tcc for complete separation of core components
in the public include