Copy stable/10@r272459 to releng/10.1 as part of
the 10.1-RELEASE process.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Copy head (r256279) to stable/10 as part of the 10.0-RELEASE cycle.

Approved by: re (implicit)
Sponsored by: The FreeBSD Foundation

Replace the non-standard disclaimer with the standard one from /COPYRIGHT

Approved by: jedgar@

mdoc(7) police: "The .Fn function".

mdoc(7) police: Use the new .In macro for #include statements.

Record -lposix1e merge with -lc.

mdoc(7) police: fix markup.

Add the following ACL editing functions:
acl_add_perm, acl_clear_perms, acl_copy_entry, acl_create_entry,
acl_delete_perm, acl_get_permset, acl_get_qualifier, acl_get_tag_type,
acl_set_permset, acl_set_qualifier, acl_set_tag_type

This brings us within 4 functions of a full ACL editing library.

Reviewed by: rwatson