news: More 5.1 updates

Mention my snapshot bug fixes, and the corresponding virsh command-line
parse tweak I added while working on the snapshot bug fixes.
Signed-off-by: NEric Blake <eblake@redhat.com>

docs/news.xml

@@ -157,6 +157,17 @@
           version.
         </description>
       </change>
+      <change>
+        <summary>
+          Batch mode virsh and virt-admin parsing improvements
+        </summary>
+        <description>
+          When parsing a single-argument command_string in batch mode,
+          virsh and virt-admin now permit newlines in addition to
+          semicolons for splitting commands, and backslash-newline for
+          splitting long lines, to be more like shell parsing.
+        </description>
+      </change>
     </section>
     <section title="Bug fixes">
       <change>
@@ -315,6 +326,16 @@
           attributes for devices without an image.
         </description>
       </change>
+      <change>
+        <summary>
+          External snapshot metadata redefinition is fixed
+        </summary>
+        <description>
+          Attempting to use VIR_DOMAIN_SNAPSHOT_CREATE_REDEFINE to
+          reinstate the metadata describing an external snapshot
+          created earlier for an offline domain no longer fails.
+        </description>
+      </change>
     </section>
   </release>
   <release version="v5.0.0" date="2019-01-15">