Merge branch 'maint'

* maint: Start 1.6.0.4 cycle add instructions on how to send patches to the mailing list with Gmail Documentation/gitattributes: Add subsection header for each attribute git send-email: avoid leaking directory file descriptors. send-pack: do not send out single-level refs such as refs/stash fix overlapping memcpy in normalize_absolute_path pack-objects: avoid reading uninitalized data correct cache_entry allocation Conflicts: RelNotes