Added info about release time deps

DEVELOPERS

@@ -15,20 +15,25 @@ You will need the following installed:
  * GNU Autoconf (>=2.68)  (http://www.gnu.org/software/autoconf/)
  * GNU Autoconf Archive   (http://www.gnu.org/software/autoconf-archive/)
  * pkg-config             (http://www.freedesktop.org/wiki/Software/pkg-config)
- 
+
 You may also need:
 
  * Sphinx                 (http://sphinx.pocoo.org/)
  * LaTex                  (http://www.latex-project.org/)
  * GNU Texinfo            (http://www.gnu.org/software/texinfo/)
  * GNU help2man           (http://www.gnu.org/software/help2man/)
+ * GnuPG                  (http://www.gnupg.org/)
+ * md5sum                 (http://www.microbrew.org/tools/md5sha1sum/)
+ * sha1sum                (http://www.microbrew.org/tools/md5sha1sum/)
 
-These optional dependencies are required for building the documentation.
+The first of these optional dependencies are required for building the
+documentation. The last three are needed to build releases.
 
 You will need these optional dependencies installed if:
 
+ * You are working on the documentation, or
  * You are preparing a distribution archive
- 
+
 However, you do not need them if:
 
  * You are building from a distribution archive, or
@@ -54,8 +59,7 @@ Optional dependencies:
     sudo apt-get install texlive-latex-extra
     sudo apt-get install texlive-fonts-recommended
     sudo apt-get install texinfo
-
-Be sure to update the version numbers to match your system's available packages.
+    sudo apt-get install gnupg
 
 Mac OS X
 ~~~~~~~~
@@ -77,6 +81,8 @@ Unless you want to install the optional dependencies, skip to the next section.
 Install what else we can with Homebrew:
 
     brew install help2man
+    brew install gnupg
+    brew install md5sha1sum
 
 If you don't already have pip installed, install it:
 
@@ -97,8 +103,8 @@ Follow the instructions to get a working LaTeX install on your system.
 Windows
 ~~~~~~~
 
-    Follow the instructions in INSTALL.Windows and build all components
-    from source, using the same Visual C++ compiler and runtime.
+Follow the instructions in INSTALL.Windows and build all components from
+source, using the same Visual C++ compiler and runtime.
 
 Bootstrapping
 -------------
@@ -154,7 +160,7 @@ Releasing
 
 The release procedure is documented here:
 
-    https://wiki.apache.org/couchdb/Release_procedure
+    https://wiki.apache.org/couchdb/Release_Procedure
 
 Unix-like Systems
 ~~~~~~~~~~~~~~~~~