fast-import: add a get-mark command

diff --git a/RelNotes b/RelNotes
index 39dc075ee01342db1cd11c47f6de0395df605976..1addbec92533510e6e368c607deb36e504bbc438 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes/1.7.3.5.txt
\ No newline at end of file
+Documentation/RelNotes/2.4.0.txt
\ No newline at end of file