* optional path to use spacks py-site-pkgs, install host-cfg for provenance
* add more comments and address review requests
* only use st-pkgs-dir when +python
* ascent does not need doxygen
* capture mpiexec if it exists
* added missing import
* flake8 fix
* default adios variant to False
* ascent develop now reqs conduit master
* optional path to use spacks py-site-pkgs, install host-cfg for provenance
* add more comments and address review requests
* only use st-pkgs-dir when +python
* ascent does not need doxygen
* capture mpiexec if it exists
* added missing import
* flake8 fix
* default adios variant to False
* ascent develop now reqs conduit master
* conduit: use hdf5 1.8 for wider output compat
* add ascent package and and deps
* proper use of site_packages_dir prop
* flake8
* add maitain, small updates
* flake8
* flake8
* fixs for docstrings for sphinx
