setup: convert setup_git_directory_gently_1 et al. to strbuf

diff --git a/RelNotes b/RelNotes
index e90dc8ee42fe41d3c4eb09d324d8d2de6aff425b..7c4ae86d0f685ca3b07163e646c242fda3a32b3c 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes-1.6.2.3.txt
\ No newline at end of file
+Documentation/RelNotes/2.0.2.txt
\ No newline at end of file