lots of fixes and improvements

* fix up fstab to take removing FDE into account
* check for a bug in abs_path
* fix getting whitelist files relative to the main script
* fix globbing from whitelists with shell globs but no "..."
* fix weird globbing bug
* fix copying symlinks
* use chroot to run some setup commands: eselect python, gcc-config,
  build-docbook-catalog
* add /media/.keep, /bin/sh symlink, /usr/lib symlink, /boot to
  baselayout whitelist, and remove a bunch of files that are generated
  from various scripts
* add etc-portage whitelist
* add gcc whitelist
* add kernel modules to the kernel whitelist