[vendor/pkgsrc] Import pax-20080110 from pkgsrc HEAD
[archivers/pax] Move pkgtools/pax to archivers

This move is supposed to have little to no impact since pax is taken from the
system by default.
[archivers/pax] Import pax-20080110 from vendor/pkgsrc

This is the same version as before, but it is now properly imported from
pkgsrc via the vendor/pkgsrc branch.
[archivers/pax] Remove local patches

- patch-aa installing pax as robotpkg_pax should not be needed anymore
  (updated depend.mk, Makefile and PLIST accordingly).
- patch-ab fixing a name clash with getline() has been fixed upstream.
[archivers/pax] Fix a BSDism in the Makefile

We don't want to install cat pages anyway, so directly drop the entire
statement inside the BSD .if/.endif.
[archivers/pax] Provide an "inplace" build of pax, for bootstrap

The inplace version is only used if pax is configured with PREFER.pax =
robotpkg. This is useful to avoid a circular dependency between pax and
pkg_install (reported by Raphael Lallement, thanks!).
[pkgtools/pkg_install] Depend on pax with the "inplace" style

This has an effect only if pax is configured with PREFER.pax = robotpkg, which
is not the default.
[pkgtools/pkgrepo2deb] Depend on pax with the "inplace" style.

This is required for building the binary package of pkg_install when PREFER.pax
is set to 'robotpkg'.
[sysdep/apr] Make sure libapr is found on gentoo
[sysdep/tinyxml] Make sure tinyxml is found on gentoo
[sysutils/ros-rospack] Make sure rospack find tinyxml on gentoo
[archivers/pax] Fix a typo in the depend.mk
[devel/ros-pluginlib] Actually use tinyxml_INCLUDE_DIRS once computed