This addresses multiple issues:
* Issue #63: initrd is build fresh each time, so tracked files do not matter.
* Issue #144: build time configuration
* Issue #123: allows us to customize the startup experience
* Issue #122: manual start-xen will go away
* Issue #25: tpmtotp PCRs are updated after reading the secret
* Issue #16: insmod now meaures modules
Reduce the size of flashrom by commenting out most flash chips,
boards and programmers.
Wrapper script to make it easier to rewrite the ROM on the x230
using the flashrom layout.
Keep the entire 12 MB ROM for flashing.
