v2.2.53
modernize build system
setfacl: Preserve special mode bits on filesystems without POSIX ACL support
getfacl: Fix minor resource leak
setfacl: Allow more than four characters in the perms field
read_acl_{comments,seq}: rename "line" to "lineno"
setfacl --restore: Silence valgrind
add __acl_ prefixes to internal symbols
Rework config.h usage