Make `git gc --auto` return immediately and run in background
if the system supports it. Default is true.
+gc.logExpiry::
+ If the file gc.log exists, then `git gc --auto` won't run
+ unless that file is more than 'gc.logExpiry' old. Default is
+ "1.day". See `gc.pruneExpire` for more ways to specify its
+ value.
+
gc.packRefs::
Running `git pack-refs` in a repository renders it
unclonable by Git versions prior to 1.5.1.2 over dumb