ItemUpdater: Implement Software.Extended Version

- Add Extended version in the MANIFEST
- Create an ExtendedVersion object
- Populate the ExtendedVersion object from MANIFEST

Resolves openbmc/openbmc#1401

Change-Id: Icb21e51a2a74c94f54ffecbd9057add4a0d3d694
Signed-off-by: Saqib Khan <khansa@us.ibm.com>
diff --git a/generate-squashfs b/generate-squashfs
index 11f0abc..6b14618 100755
--- a/generate-squashfs
+++ b/generate-squashfs
@@ -104,7 +104,8 @@
 
 echo "Creating MANIFEST for the image"
 manifest_location="${scratch_dir}/MANIFEST"
-echo -e "purpose=host\nversion=$version" >> $manifest_location
+echo -e "purpose=host\nversion=$version\n\
+extended_version=$extended_version" >> $manifest_location
 
 echo "Generating tarball to contain the SquashFS image and its MANIFEST"
 tar -cvf $outfile $manifest_location ${scratch_dir}/pnor.xz.squashfs