classes/buildhistory: write out files in UTF-8 format
If the package information contained unicode characters (for example, in
the package file listing) then writing them out as ASCII would fail, so
write them out using codecs.open() instead of open() using UTF-8. This
fixes ca-certificates failing in do_packagedata when buildhistory is
enabled.
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
