toaster: Y9137 get packages from sstate

This addresses the missing packages part of Y9137. This patch allows us to see
packages that came from a setscene.
Testing it is a little hard:
1) You can add the following to your local.conf in a toaster dir:
SSTATE_MIRRORS="file://.* http://downloads.yoctoproject.org/tools/support/toaster/sstate-test/master/sstate-cache/PATH"
This might also work:
SSTATE_MIRRORS="file://.* http://sstate.yoctoproject.org/dev/PATH"
and build dropbear in a LOCAL project. You should see ~322 pkgs built.

The hard way to test this is to:
1) start toaster
2) build dropbear as a local project
3) stop toaster
4) rm everything except sstate-cache/ and conf/
5) restart toaster
6) build dropbearas a local project. it should come from sstate and downloads should remain empty.

Note, there is still a big difference between the pkgs we get from a build ~2844 and the ones we get from setscening. The setscening doesn't package:
*locales
glibc-charmap*
glibc-gconv*
perl-module*
ncurses-lib*
as they seem to be unnecessary in order to be able to package dropbear.

---
This does not address the need to change "packages built" to something more generic like packages in the UI.

-b
an Intel employee

The following changes since commit 325a35c43df83d4268fc54a8955ee785f6a1f6fe:

toaster: update the meta-yocto toaster configuration file (2016-03-07 21:36:03 -0800)

are available in the git repository at:

git://git.yoctoproject.org/poky-contrib bavery/toaster/getPkgsFromSstate-Y9137V2
http://git.yoctoproject.org/cgit.cgi/poky-contrib/log/?h=bavery/toaster/getPkgsFromSstate-Y9137V2

brian avery (1):
toaster: show packages that were setscened into existence too

 meta/classes/toaster.bbclass | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

--
1.9.1