Fixes [YOCTO #1949]
Updated the following tasks to note that they "clean" out some
areas when run:
do_populate_sysroot
do_deploy
Also made some notes to the do_cleansstate task about attempting
to clean remote mirrors.
And, made a change to do_cleanall to specifically mention that
DL_DIR is cleaned.
(From yocto-docs rev: 7e532b17ccd89e43d3661c733ce1f06a52066c29)
Signed-off-by: Scott Rifenbark <scott.m.rifenbark@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>