In 2014, the update of the diagnostics recipes from 1.8.3 to 1.8.4
failed due to reasons that seem not to be relevant anymore in the
current version 1.8.10. As the diagnostic-aggregator recipe failed
with gcc6 (cf. https://github.com/bmwcarit/meta-ros/issues/392

),
I revisited the diagnostics recipes and this commit updates them.
The current diagnostics recipes in version 1.8.10 do not fail with
gcc6, and is one step forward to build meta-ros with gcc6.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@oss.bmw-carit.de>

The meta-oe provides since commit 8700ba38@openembedded/meta-openembedded
(commit date: 2016-01-14) [1] a recipe for the POCO C++ Library.
Consequently, this commit removes the libpoco recipe in the
meta-ros layer.

As meta-ros already depends on the meta-oe layer, the poco
recipe is available in release version since 2016-01-14,
and the poco recipe in meta-ros is redundant for these versions.
However, this commit still provides the currently latest poco
recipe [2] for users that are not using a recent version of the
meta-oe layer.

[1] http://cgit.openembedded.org/meta-openembedded/commit?id=8700ba38804af3c27f3662737f679afa1bdc86da
[2] http://cgit.openembedded.org/meta-openembedded/tree/meta-oe/recipes-support/poco?id=0a2bd4f9784253a8a8dda35e3c4dbd75931d3564



Signed-off-by: Lukas Bulwahn <lukas.bulwahn@oss.bmw-carit.de>

The recent versions of the rosbridge_library package does not depend
on python-pytz anymore. So, this commit removes the dependency in
the recipe file and removes the now unneeded python-pytz recipe.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@oss.bmw-carit.de>

Bitbake gives a dependency error when IMAGE_FEATURES += " dev-pkgs" is set.

This is because the urdfdom-headers package contains headers only, as a
result bitbake packages them into urdfdom-headers-dev and leaves
urdfdom-headers empty.

Since there are no files to be packaged into urdfdom-headers bitbake
doesn't create the package. urdfdom-headers is a dependency
of urdfdom-headers-dev by default so bitbake errors when building an image
with dev-pkgs enabled.

ALLOW_EMPTY tells bitbake to create a package even when nothing is in it.
This resolves the dependency issue of urdfdom-headers-dev
http://www.embeddedlinux.org.cn/OEManual/recipes_packages.html