doc: remove references to gittutorial-2

Redirect folks to `gitdatamodel` instead, since every time it's
referenced the intent is to explain objects, references, blobs, etc.

The update to `gittutorial` isn't very carefully thought through since
we're planning to delete that entire document anyway. It's just there to
maintain some internal consistency.

Signed-off-by: Julia Evans <julia@jvns.ca>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/MyFirstObjectWalk.adoc

@@ -145,7 +145,7 @@ used to track the allocated size of the list.
 Per entry, we find:
 
 `item` is the object provided upon which to base the object walk. Items in Git
-can be blobs, trees, commits, or tags. (See `Documentation/gittutorial-2.adoc`.)
+can be blobs, trees, commits, or tags. (See `Documentation/gitdatamodel.adoc`.)
 
 `name` is the object ID (OID) of the object - a hex string you may be familiar
 with from using Git to organize your source in the past. Check the tutorial

Documentation/git.adoc

@@ -1208,7 +1208,7 @@ the Git Security mailing list <git-security@googlegroups.com>.
 
 SEE ALSO
 --------
-linkgit:gittutorial[7], linkgit:gittutorial-2[7],
+linkgit:gittutorial[7],
 linkgit:giteveryday[7], linkgit:gitcvs-migration[7],
 linkgit:gitglossary[7], linkgit:gitdatamodel[7],
 linkgit:gitcore-tutorial[7], linkgit:gitcli[7],

Documentation/gitcore-tutorial.adoc

@@ -1645,7 +1645,6 @@ to follow, not easier.
 SEE ALSO
 --------
 linkgit:gittutorial[7],
-linkgit:gittutorial-2[7],
 linkgit:gitcvs-migration[7],
 linkgit:git-help[1],
 linkgit:giteveryday[7],

Documentation/gitcvs-migration.adoc

@@ -194,7 +194,7 @@ repositories without the need for a central maintainer.
 SEE ALSO
 --------
 linkgit:gittutorial[7],
-linkgit:gittutorial-2[7],
+linkgit:gitdatamodel[7],
 linkgit:gitcore-tutorial[7],
 linkgit:gitglossary[7],
 linkgit:giteveryday[7],

Documentation/gitglossary.adoc

@@ -14,7 +14,6 @@ SEE ALSO
 --------
 linkgit:gitdatamodel[7],
 linkgit:gittutorial[7],
-linkgit:gittutorial-2[7],
 linkgit:gitcvs-migration[7],
 linkgit:giteveryday[7],
 link:user-manual.html[The Git User's Manual]

Documentation/gittutorial.adoc

@@ -617,24 +617,12 @@ Next Steps
 ----------
 
 This tutorial should be enough to perform basic distributed revision
-control for your projects.  However, to fully understand the depth
-and power of Git you need to understand two simple ideas on which it
-is based:
+control for your projects.  However, to fully understand the Git
+documentation, it's useful to learn how Git stores the history of
+your project in its database. See linkgit:gitdatamodel[7] for an
+explanation.
 
-  * The object database is the rather elegant system used to
-    store the history of your project--files, directories, and
-    commits.
-
-  * The index file is a cache of the state of a directory tree,
-    used to create commits, check out working directories, and
-    hold the various trees involved in a merge.
-
-Part two of this tutorial explains the object
-database, the index file, and a few other odds and ends that you'll
-need to make the most of Git. You can find it at linkgit:gittutorial-2[7].
-
-If you don't want to continue with that right away, a few other
-digressions that may be interesting at this point are:
+A few other commands that may be interesting:
 
   * linkgit:git-format-patch[1], linkgit:git-am[1]: These convert
     series of git commits into emailed patches, and vice versa,
@@ -657,7 +645,6 @@ digressions that may be interesting at this point are:
 
 SEE ALSO
 --------
-linkgit:gittutorial-2[7],
 linkgit:gitcvs-migration[7],
 linkgit:gitcore-tutorial[7],
 linkgit:gitglossary[7],

command-list.txt

@@ -244,7 +244,6 @@ gitrepository-layout                    userinterfaces
 gitrevisions                            userinterfaces
 gitsubmodules                           guide
 gittutorial                             guide
-gittutorial-2                           guide
 gitweb                                  ancillaryinterrogators
 gitworkflows                            guide
 scalar                                  mainporcelain