WIP adding post install setup
try extconf.rb
warning/info support, default is error
restructured test-like output support
broken but better post install config
Revert "WIP:still broken, but less drastically, and for logic rather than stupidity reasons now"; in a branch now

This reverts commit ea8b0ccddec9d19e038fd8ed5b8c1d54ef01cd66.
Revert "WIP: untested but theoretically close disjoint_code capability"; in a branch now

This reverts commit f70ff4ec9c60e5a3c9d15ec04b8847370c9ab62c.