text: more Git updates

A few updates for Git that were missed, including the new version
numbering scheme for nightly snapshot tarballs.

HACKING

@@ -21,18 +21,18 @@ Overview
 
 This file is here for those who are building/exploring OMPI in its
 source code form, most likely through a developer's tree (i.e., a
-Subversion or Mercurial checkout).
+Git clone).
 
 
 Debugging vs. Optimized Builds
 ==============================
 
-If you are building Open MPI from a Subversion checkout, the default
-build includes a lot of debugging features.  This happens
-automatically when when configure detects the hidden ".git" Git meta
-directory (that is present in all Git clones) in your source tree, and
-therefore activates a number of developer-only debugging features in
-the Open MPI code base.
+If you are building Open MPI from a Git clone, the default build
+includes a lot of debugging features.  This happens automatically when
+when configure detects the hidden ".git" Git meta directory (that is
+present in all Git clones) in your source tree, and therefore
+activates a number of developer-only debugging features in the Open
+MPI code base.
 
 By definition, debugging builds will perform [much] slower than
 optimized builds of Open MPI.  You should *NOT* conduct timing tests

INSTALL

@@ -8,7 +8,7 @@ Copyright (c) 2004-2005 High Performance Computing Center Stuttgart,
                         University of Stuttgart.  All rights reserved.
 Copyright (c) 2004-2005 The Regents of the University of California.
                         All rights reserved.
-Copyright (c) 2008-2010 Cisco Systems, Inc.  All rights reserved.
+Copyright (c) 2008-2014 Cisco Systems, Inc.  All rights reserved.
 $COPYRIGHT$
 
 Additional copyrights may follow
@@ -30,8 +30,8 @@ Developer Builds
 ================
 
 If you have checked out a DEVELOPER'S COPY of Open MPI (i.e., you
-checked out from subversion), you should read the HACKING file before
-attempting to build Open MPI.  You must then run:
+cloned from Git), you should read the HACKING file before attempting
+to build Open MPI.  You must then run:
 
 shell$ ./autogen.pl
 

README

@@ -1424,8 +1424,9 @@ binary interface (ABI) compatibility implications.
 Software Version Number
 -----------------------
 
-Open MPI's version numbers are the union of several different values:
-major, minor, release, and an optional quantifier.
+The version number of Open MPI distribution tarballs are the union of
+several different values: major, minor, release, and an optional
+quantifier.
 
   * Major: The major number is the first integer in the version string
     (e.g., v1.2.3). Changes in the major number typically indicate a
@@ -1471,24 +1472,39 @@ major, minor, release, and an optional quantifier.
     o rcX: Indicates a release candidate. X is an integer
       indicating the number of the release candidate (e.g., v1.2.3rc4
       indicates the 4th release candidate of version 1.2.3).
-    o rV or hgV: Indicates the Subversion / Mercurial repository
-      number string that the release was made from (V is usually an
-      integer for Subversion releases and usually a string for
-      Mercurial releases). Although all official Open MPI releases are
-      tied to a single, specific Subversion or Mercurial repository
-      number (which can be obtained from the ompi_info command), only
-      some releases have the Subversion / Mercurial repository number
-      in the version number. Development snapshot tarballs, for
-      example, have the Subversion repository included in the version
-      to reflect that they are a development snapshot of an upcoming
-      release (e.g., v1.2.3r1234 indicates a development snapshot of
-      version 1.2.3 corresponding to Subversion repository number
-      1234). 
+    o Prior to October 2014, nightly snapshot tarballs would include a
+      repository version number as well, such as r1234, indicating
+      that that snapshot tarball was built at Subversion r1234).
 
-    Quantifiers may be mixed together -- for example v1.2.3rc7r2345
-    indicates a development snapshot of an upcoming 7th release
-    candidate for version 1.2.3 corresponding to Subversion repository
-    number 2345.
+Starting in October 2014, although the major, minor, and release
+values (and optional quantifiers) are reported in Open MPI nightly
+snapshot tarballs, the filenames of these snapshot tarballs follow a
+slightly different convention.
+
+Specifically, the snapshot tarball filename contains three distinct
+values:
+
+   * Most recent Git tag name on the branch from which the tarball was
+     created.
+
+   * An integer indicating how many Git commits have occurred since
+     that Git tag.
+
+   * The Git hash of the tip of the branch.
+
+For example, a snapshot tarball filename of
+"openmpi-v1.8.2-57-gb9f1fd9.tar.bz2" indicates that this tarball was
+created from the v1.8 branch, 57 Git commits after the "v1.8.2" tag,
+specifically at Git hash gb9f1fd9.
+
+Open MPI's Git master branch contains a single "dev" tag.  For
+example, "openmpi-dev-8-gf21c349.tar.bz2" represents a snapshot
+tarball created from the master branch, 8 Git commits after the "dev"
+tag, specifically at Git hash gf21c349.
+
+The exact value of the "number of Git commits past a tag" integer is
+fairly meaningless; its sole purpose is to provide an easy,
+human-recognizable ordering for snapshot tarballs.
 
 Shared Library Version Number
 -----------------------------