made the pack completely portable and wrote relevent bat files to go with it

gitportable/mingw64/share/doc/git-doc/RelNotes/2.5.1.adoc

@@ -0,0 +1,65 @@
+Git v2.5.1 Release Notes
+========================
+
+Fixes since v2.5
+----------------
+
+ * Running an aliased command from a subdirectory when the .git thing
+   in the working tree is a gitfile pointing elsewhere did not work.
+
+ * Often a fast-import stream builds a new commit on top of the
+   previous commit it built, and it often unconditionally emits a
+   "from" command to specify the first parent, which can be omitted in
+   such a case.  This caused fast-import to forget the tree of the
+   previous commit and then re-read it from scratch, which was
+   inefficient.  Optimize for this common case.
+
+ * The "rev-parse --parseopt" mode parsed the option specification
+   and the argument hint in a strange way to allow '=' and other
+   special characters in the option name while forbidding them from
+   the argument hint.  This made it impossible to define an option
+   like "--pair <key>=<value>" with "pair=key=value" specification,
+   which instead would have defined a "--pair=key <value>" option.
+
+ * A "rebase" replays changes of the local branch on top of something
+   else, as such they are placed in stage #3 and referred to as
+   "theirs", while the changes in the new base, typically a foreign
+   work, are placed in stage #2 and referred to as "ours".  Clarify
+   the "checkout --ours/--theirs".
+
+ * An experimental "untracked cache" feature used uname(2) in a
+   slightly unportable way.
+
+ * "sparse checkout" misbehaved for a path that is excluded from the
+   checkout when switching between branches that differ at the path.
+
+ * The low-level "git send-pack" did not honor 'user.signingkey'
+   configuration variable when sending a signed-push.
+
+ * An attempt to delete a ref by pushing into a repository whose HEAD
+   symbolic reference points at an unborn branch that cannot be
+   created due to ref D/F conflict (e.g. refs/heads/a/b exists, HEAD
+   points at refs/heads/a) failed.
+
+ * "git subtree" (in contrib/) depended on "git log" output to be
+   stable, which was a no-no.  Apply a workaround to force a
+   particular date format.
+
+ * "git clone $URL" in recent releases of Git contains a regression in
+   the code that invents a new repository name incorrectly based on
+   the $URL.  This has been corrected.
+   (merge db2e220 jk/guess-repo-name-regression-fix later to maint).
+
+ * Running tests with the "-x" option to make them verbose had some
+   unpleasant interactions with other features of the test suite.
+   (merge 9b5fe78 jk/test-with-x later to maint).
+
+ * "git pull" in recent releases of Git has a regression in the code
+   that allows custom path to the --upload-pack=<program>.  This has
+   been corrected.
+
+ * pipe() emulation used in Git for Windows looked at a wrong variable
+   when checking for an error from an _open_osfhandle() call.
+
+Also contains typofixes, documentation updates and trivial code
+clean-ups.