This introduces a libxml2-dev package which contains most stuff
required for developing against libxml2 (on the target), and
the libxml2-utils package which contains the xmllint and xmlcatalog
command line binaries which are provided by libxml2.

Reported-by: Valentín Kivachuk <vk18496@gmail.com>
Signed-off-by: Michael Heimpold <mhei@heimpold.de>