Remove lib/sfio/features/stdio
Remove lib/sfio/features/stdio

This file is never used in the build process and can therefore be removed.

ellson/graphviz,ellson/graphviz,ellson/graphviz,ellson/graphviz,ellson/graphviz,ellson/graphviz,ellson/graphviz,ellson/graphviz,ellson/graphviz,ellson/graphviz,ellson/graphviz