Merge branch 'maint'

* maint:
  base85: Make the code more obvious instead of explaining the non-obvious
  base85: encode_85() does not use the decode table
  base85 debug code: Fix length byte calculation
  Documentation: tiny git config manual tweaks
  Documentation: git gc packs refs by default now
  checkout -m: do not try to fall back to --merge from an unborn branch

diff --cc Documentation/config.txt
Simple merge