modify bashrc to setup git correctly,
  add some test for verifying image content after build finished,
  remove --noenable_rootfs_verification flag (get some security back!),
  clean a bit,
  update README.

nayuos: Add logo, hash names in hashes.txt, keep_cache parameter (experimental), gzip instead of tar + gzip the final images.

nayuos: Add script to modify the image after build (create two images: Chromium and Nayu) + script dir.

nayuos: Adding a script to /etc/run for downloading Chromium OS sources + building instead of doing it during instanciation.