layer: update configuration and dependencies

Add in support for optional bbappends based on the presence of other
layers in the project and move the lxc recipe to a meta-virtualization
location.

Signed-off-by: Joe MacDonald <joe_macdonald@mentor.com>

README

@@ -34,6 +34,19 @@ the Yocto Project website:
 
 http://www.yoctoproject.org
 
+This layer also optionally depends on the following layers:
+
+URI: git://github.com/openembedded/meta-oe.git
+branch: master
+revision: HEAD
+layers: meta-oe
+        meta-networking
+        meta-python
+
+URI: git://git.yoctoproject.org/meta-virtualization
+branch: master
+revision: HEAD
+
 
 Maintenance
 -----------

conf/layer.conf

@@ -5,6 +5,11 @@ BBPATH .= ":${LAYERDIR}"
 BBFILES += "${LAYERDIR}/recipes-*/*/*.bb \
             ${LAYERDIR}/recipes-*/*/*.bbappend"
 
+# Let us add layer-specific bbappends which are only applied when that
+# layer is included in our configuration
+BBFILES += "${@' '.join('${LAYERDIR}/%s/recipes*/*/*.bbappend' % layer \
+               for layer in BBFILE_COLLECTIONS.split())}"
+
 BBFILE_COLLECTIONS += "selinux"
 BBFILE_PATTERN_selinux = "^${LAYERDIR}/"
 BBFILE_PRIORITY_selinux = "5"
@@ -15,8 +20,4 @@ LAYERVERSION_selinux = "1"
 
 LAYERDEPENDS_selinux = " \
     core \
-    meta-python \
-    networking-layer \
-    openembedded-layer \
-    virtualization-layer \
 "