Start to feed 2.7 changelog.

debian/changelog

 tails (2.7) UNRELEASED; urgency=medium
 
-  * Dummy entry.
+  * Major new features and changes
+    - Install Tor 0.2.8.8. (Closes: #11832)
+
+  * Minor improvements
+    - Ship Let's encrypt intermediate certificate to prepare the
+      the next certificate renewal of our website. Also unify the
+      way our upgrades and security checkers verify this SSL
+      certificate using our dedicated perl lib code. (Closes: #11810)
+
+  * Bugfixes
+    - Fix multiarch support in Synaptic. (Closes: #11820)
+
+  * Test suite
+    - Test incremental upgrades. (Closes: #6309)
 
  -- Tails developers <tails@boum.org>  Mon, 03 Oct 2016 23:06:51 +0200