#54 Make rbmk build system use kconfig for *everything*

re-write/re-factor parts of build system. make everything be done with make menuconfig interface like in coreboot / linux kernel configs for coreboot boards still added in advance, but write automated scripts for handling that stuff however, stuff like cbrevision, grub revision etc specified in kconfig have build system use that only minimal changes (in grand scheme of things) needed to do this. there are a few things i need to do first. right now these are just concepts in my head. gonna do something on this soon-ish, in a special branch. when ready will merge in master branch