FEATURES="userfetch" is now enabled by default. Depending on your ${DISTDIR}
* permissions, this may result in Permission Denied errors. If you would like
* to fetch with superuser privileges, add FEATURES="-userfetch" to make.conf.
*
* The world file now supports slot atoms such as 'sys-devel/gcc:3.4'. In some
* cases, emerge --depclean may remove slots that it would not have removed
* in the past. The emerge --noreplace command can be used to add an atom to
* the world file and prevent matching packages from being removed. A slot
* atom will be recorded in the world file for any atom that is precise enough
* to identify a specific slot.
*
* For help with using portage please consult the Gentoo Handbook
* at http://www.gentoo.org/doc/en/handbook/handbook-x86.xml?part=3