Default disable autounmask package.accept_keywords/mask changes (bug 658648)

Add emerge --autounmask-license and --autounmask-use options which are
enabled by default, and disable package.accept_keywords/mask changes by
default. For backward compatibility, previous behavior of
--autounmask=y and --autounmask=n is entirely preserved. Users can
get the old behavior simply by adding --autounmask to the make.conf
EMERGE_DEFAULT_OPTS variable.

Bug: https://bugs.gentoo.org/658648
Signed-off-by: Zac Medico <zmedico@gentoo.org>
5 files changed