bb-determine-layers: quiet BBFILE_PATTERN def warning

Signed-off-by: Christopher Larson <chris_larson@mentor.com>
(cherry picked from commit d5ff9a2bd25cf4ead60007b1b5dca54a63c2d0f0)

Signed-off-by: Michael Brown <mw_brown@mentor.com>
bb-determine-layers: find optional layer deps in the base layers too

Signed-off-by: Christopher Larson <chris_larson@mentor.com>
(cherry picked from commit da082a877ee5c9f70c220625dcf8d53f571f886d)

Signed-off-by: Michael Brown <mw_brown@mentor.com>
setup-environment, setup-builddir: rework required/optional

Rework handling of required vs optional layers to match the layer readme.

Signed-off-by: Christopher Larson <chris_larson@mentor.com>
(cherry picked from commit 630fcb6f3d0f7a20319e9a6859e677617997b750)

Signed-off-by: Michael Brown <mw_brown@mentor.com>
Merge pull request #11 from mbrown9764/kergoth-bb-det-layers

Kergoth bb det layers