Update notes for submitted changes

* Add tests for updating single refs to missing objects
* Fix deleting symrefs
* RefDirectory: Throw exception if CAS of packed ref list fails
* ReceiveCommand: Explicitly check constructor preconditions
* BatchRefUpdate: Document when getPushOptions is null

00/a72e22e6d5a4416b8f2484643d25c94d805c96

@@ -0,0 +1,7 @@
+Code-Review+2: David Pursehouse <david.pursehouse@gmail.com>
+Verified+1: Hudson CI
+Submitted-by: David Pursehouse <david.pursehouse@gmail.com>
+Submitted-at: Mon, 24 Jul 2017 03:38:42 -0400
+Reviewed-on: https://git.eclipse.org/r/100768
+Project: jgit/jgit
+Branch: refs/heads/master

21/ec281f3e53e72edd77ea3ef142c953ebe0c465

@@ -0,0 +1,7 @@
+Code-Review+2: Matthias Sohn <matthias.sohn@sap.com>
+Verified+1: Hudson CI
+Submitted-by: David Pursehouse <david.pursehouse@gmail.com>
+Submitted-at: Mon, 24 Jul 2017 03:38:42 -0400
+Reviewed-on: https://git.eclipse.org/r/100769
+Project: jgit/jgit
+Branch: refs/heads/master

28/202a67586931f1adf5b4a612e85f559b9dbe43

@@ -0,0 +1,7 @@
+Code-Review+2: Terry Parker <tparker@google.com>
+Verified+1: Hudson CI
+Submitted-by: David Pursehouse <david.pursehouse@gmail.com>
+Submitted-at: Mon, 24 Jul 2017 03:38:42 -0400
+Reviewed-on: https://git.eclipse.org/r/100925
+Project: jgit/jgit
+Branch: refs/heads/master

9c/33f7364d41956240818ba12d8b79d5ea846162

@@ -0,0 +1,7 @@
+Code-Review+2: Terry Parker <tparker@google.com>
+Verified+1: Hudson CI
+Submitted-by: David Pursehouse <david.pursehouse@gmail.com>
+Submitted-at: Mon, 24 Jul 2017 03:38:42 -0400
+Reviewed-on: https://git.eclipse.org/r/100770
+Project: jgit/jgit
+Branch: refs/heads/master

f5/29fa6729a9b8b5c1329bf75639d26b0067f9d9

@@ -0,0 +1,7 @@
+Verified+1: Hudson CI
+Code-Review+2: Matthias Sohn <matthias.sohn@sap.com>
+Submitted-by: David Pursehouse <david.pursehouse@gmail.com>
+Submitted-at: Mon, 24 Jul 2017 03:38:42 -0400
+Reviewed-on: https://git.eclipse.org/r/100931
+Project: jgit/jgit
+Branch: refs/heads/master