Merge branch 'maint'

Merge branch 'maint'

* maint:
  revision traversal: --unpacked does not limit commit list anymore.
  Continue traversal when rev-list --unpacked finds a packed commit.
  Use memmove instead of memcpy for overlapping areas
  quote.c: ensure the same quoting across platforms.
  Surround "#define DEBUG 0" with "#ifndef DEBUG..#endif"