build: drop attrincludedir, use pkgincludedir

Automake already provides a variable for
${includedir}/${PACKAGE_NAME}; use it.

Acked-by: Mike Frysinger <vapier@gentoo.org>
avoid glibc-specific DECLS defines

This matches what we do in all the other headers.
build: make use of an aux-dir to stow away helper scripts

Acked-by: Mike Frysinger <vapier@gentoo.org>
build: ship a pkgconfig file for libattr
include examples/ in dist tarball

We don't want to build this, but we do want to include it in the
release, so add it to EXTRA_DIST.
test: fix cleanup & running as root

This fixes a bug when doing the cleanup of tests in a subdir by making
sure we chdir back to our starting point.

We also move the root test out of XFAIL and instead do the root checking
at runtime.  If we are root, the test passes nicely, otherwise it marks
itself as SKIP quickly.

These are fixing issues noticed when doing the update to libacl.