Catch-up with git version tags

* update debian/changelog
* update TODO-RELEASE
* add comments to Makefile.am and TODO-RELEASE to simplify the process
  in future
* add link to libtool docs to Makefile.am to simplify LIBVERSION
  maintenance

Related: OS#1861
Change-Id: I22c257e357f597519120232d742d6a61289db021
diff --git a/debian/changelog b/debian/changelog
index 0877d27..a5ca3d6 100644
--- a/debian/changelog
+++ b/debian/changelog
@@ -1,3 +1,29 @@
+libosmocore (0.9.6) unstable; urgency=medium
+
+  * doc: osmocom-authn-protocol.txt: fix numbering, mark unused sync msgs
+  * New upstream release of libosmocore.
+
+ -- Max <msuraev@sysmocom.de>  Tue, 13 Dec 2016 18:23:56 +0100
+
+libosmocore (0.9.5) unstable; urgency=medium
+
+  * fix: DLGSUP logging category "unusable"
+  * New upstream release of libosmocore.
+  * ph_data_param struct changed / Extend L1SAP PH-DATA with measurement information
+  * size of ph_tch_param struct changed / Extend with RTP Marker
+  * size of struct log_target changed / Extend with GSMTAP
+
+ -- Max <msuraev@sysmocom.de>  Tue, 13 Dec 2016 18:22:56 +0100
+
+libosmocore (0.9.4) unstable; urgency=medium
+
+  * New upstream release of libosmocore.
+  * Internal API for GPRS cipher implementors updated to accommodate for arbitrary key lengths
+  * external talloc dependency / internal talloc removal
+  * size of ph_data_param struct changed / Extend L1SAP PH-DATA with presence information
+
+ -- Max <msuraev@sysmocom.de>  Tue, 13 Dec 2016 18:21:56 +0100
+
 libosmocore (0.9.3) unstable; urgency=medium
 
   * Send all stats values after re-configuration.