build+docs: align minimum requirements with ndn-cxx/NFD

 * Recommend boost >= 1.65.1 and gcc >= 7.4.0
 * Require clang >= 4.0, or Xcode >= 9.0 on macOS
 * Silence an ABI-related diagnostic message from gcc on armv7
 * Update waf to version 2.0.21
 * Make graphviz optional for building documentation
 * Sync sphinx configuration

Change-Id: Ib271da841cd12e7595ae83d75bd0fc681f8c231f
diff --git a/docs/releases.rst b/docs/releases.rst
index 716d7c9..39b1403 100644
--- a/docs/releases.rst
+++ b/docs/releases.rst
@@ -2,24 +2,12 @@
 +++++++++++++
 
 .. toctree::
+   :glob:
    :hidden:
    :maxdepth: 1
+   :reversed:
 
-   release-notes/release-notes-0.6.0
-   release-notes/release-notes-0.5.2
-   release-notes/release-notes-0.5.1
-   release-notes/release-notes-0.5.0
-   release-notes/release-notes-0.4.3
-   release-notes/release-notes-0.4.2
-   release-notes/release-notes-0.4.1
-   release-notes/release-notes-0.4.0
-   release-notes/release-notes-0.3.2
-   release-notes/release-notes-0.3.1
-   release-notes/release-notes-0.3.0
-   release-notes/release-notes-0.2.2
-   release-notes/release-notes-0.2.1
-   release-notes/release-notes-0.2.0
-   release-notes/release-notes-0.1.0
+   release-notes/*
 
 * **NLSR version 0.6.0**
   (:doc:`Release Notes <release-notes/release-notes-0.6.0>`, `Documentation <https://named-data.net/doc/NLSR/0.6.0/>`__)