setup: convert setup_git_directory_gently_1 et al. to strbuf

diff --git a/RelNotes b/RelNotes
index 00e77229ddadcb8a13b10b693a96bd76a4cb9f33..7c4ae86d0f685ca3b07163e646c242fda3a32b3c 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes-1.7.1.txt
\ No newline at end of file
+Documentation/RelNotes/2.0.2.txt
\ No newline at end of file