docs: Prepare release notes for version 0.3.1

Change-Id: I1b2f1241af8e62d042547138f92fb2bc5f7c9265
Refs: #2588
diff --git a/docs/RELEASE_NOTES.rst b/docs/RELEASE_NOTES.rst
index 6c7b33a..e1b580d 100644
--- a/docs/RELEASE_NOTES.rst
+++ b/docs/RELEASE_NOTES.rst
@@ -3,6 +3,68 @@
 ndn-cxx Release Notes
 ---------------------
 
+ndn-cxx v0.3.1 (changes since version 0.3.0)
+++++++++++++++++++++++++++++++++++++++++++++
+
+Release date: March 3, 2015
+
+New features:
+^^^^^^^^^^^^^
+
+- **Management**
+
+  - Add isConnected() in :ndn-cxx:`signal::Connection` and :ndn-cxx:`signal::ScopedConnection`
+    (:issue:`2308`)
+
+  - Extend :ndn-cxx:`DummyClientFace` to process :ndn-cxx:`LocalControlHeader` (:issue:`2510`)
+
+  - Add CachingPolicy to :ndn-cxx:`LocalControlHeader` (:issue:`2183`)
+
+Updates and bug fixes:
+^^^^^^^^^^^^^^^^^^^^^^
+
+- **Wire encoding**
+
+  - Refactoring of :ndn-cxx:`EncodingImpl` class template (``EncodingBuffer`` and
+    ``EncodingEstimator``) (:issue:`2494`, :issue:`2490`)
+
+  - Change :ndn-cxx:`Block::fromBuffer` return type (:issue:`2553`)
+
+- **Miscellaneous tools**
+
+  - Mark ``Digest<Hash>::operator==`` as unsuitable in a security sensitive context
+    (:issue:`2395`)
+
+  - Restrict destruction of Signal from handler (:issue:`2313`)
+
+- **Documentation**
+
+  - Correct function names in security library tutorial (:issue:`2474`)
+
+  - Remind users to reinstall ports after OSX upgrade (:issue:`2284`)
+
+- **Tests**
+
+  - Fix global buffer overflow in ``ImplicitSha256Digest`` test case (:issue:`2307`)
+
+  - Change naming conventions for unit test files and test suite names (:issue:`2497`)
+
+- **Build**
+
+  - Explicitly define ``_GLIBCXX_USE_NANOSLEEP``, necessary for gcc < 4.8 in some environments
+    (:issue:`2499`)
+
+Removed:
+^^^^^^^^
+
+- Delete deprecated ``Block(std::istream&)`` constructor (:issue:`2241`)
+
+- Delete deprecated ``ndn::ptr_lib``, ``ndn::func_lib`` (:issue:`2110`)
+
+- Delete deprecated ``MetaInfo::TYPE_*`` (:issue:`2170`)
+
+****************************************************************************
+
 ndn-cxx v0.3.0 (changes since version 0.2.0)
 ++++++++++++++++++++++++++++++++++++++++++++
 
@@ -243,6 +305,8 @@
 
 - unused ``openssl`` dependency
 
+****************************************************************************
+
 ndn-cxx v0.2.0 (changes since version 0.1.0)
 ++++++++++++++++++++++++++++++++++++++++++++
 
@@ -418,7 +482,7 @@
   In applications, periodic events should be just re-scheduled within the callback for
   single-shot events.
 
-
+****************************************************************************
 
 ndn-cxx v0.1.0
 ++++++++++++++