refactored prelude printing and file names

integration/CMakeDemo/codegen_config.py

src/pystencilssfg/cli.py

src/pystencilssfg/configuration.py

src/pystencilssfg/emitters/header_source_pair.py

src/pystencilssfg/emitters/jinja_filters.py

...ystencilssfg/emitters/templates/HeaderSourcePair.tmpl.cpp

src/pystencilssfg/emitters/templates/HeaderSourcePair.tmpl.h

src/pystencilssfg/generator.py