setup: convert setup_git_directory_gently_1 et al. to strbuf

diff --git a/RelNotes b/RelNotes
index 81eb3c2271e534c04ec65227b45da12ab6eccf77..7c4ae86d0f685ca3b07163e646c242fda3a32b3c 120000 (symlink)
--- a/RelNotes
+++ b/RelNotes
@@ -1 +1 @@
-Documentation/RelNotes/1.7.7.7.txt
\ No newline at end of file
+Documentation/RelNotes/2.0.2.txt
\ No newline at end of file