Drop 1.7.11.x items from 1.7.12 release notes

Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/RelNotes/1.7.12.txt

@@ -140,23 +140,10 @@ details).
    comparison.
    (merge cb2912c hv/link-alt-odb-entry later to maint).
 
- * "git checkout <branchname>" to come back from a detached HEAD state
-   incorrectly computed reachability of the detached HEAD, resulting
-   in unnecessary warnings.
-   (merge add416a jk/maint-checkout-orphan-check-fix later to maint).
-
- * The documentation for revision range specifiers (e.g. A..B, A^@)
-   has been updated.
-   (merge ca5ee2d mh/maint-revisions-doc later to maint).
-
  * "git submodule add" was confused when the superproject did not have
    its repository in its usual place in the working tree and GIT_DIR
    and GIT_WORK_TREE was used to access it.
 
- * "git mergetool" did not support --tool-help option to give the list
-   of supported backends, like "git difftool" does.
-   (merge 109859e jc/mergetool-tool-help later to maint).
-
  * "git commit --amend" let the user edit the log message and then died
    when the human-readable committer name was given insufficiently by
    getpwent(3).