* Introduce a macro to conditionally execute tests. This avoids
skipping the entire test if some parts require systemd
* Skip the journal tests when no /etc/machine-id is present
* Change test-catalog to load the catalog from the source directory
of systemd.
* /proc/PID/comm got introduced in v2.6.33 but travis is still
using v2.6.32.
* Enable make check and make distcheck on the travis build
* Use -D"CATALOG_DIR=STR($(abs_top_srcdir)/catalog)" as a STRINGIY
would result in the path '/home/ich/source/linux' to be expanded
to '/home/ich/source/1' as linux is defined to 1.
Instruct travis-ci to build systemd and create a tarball. In case
of an error travis-ci will complain on IRC. The systemd testsuite
currently requires the host to have a recent version of systemd
installed and running. This is not the case for the Ubuntu VM of
travis-ci. This means make check and make distcheck will result in
a build failure and to avoid this these commands are not executed.
This requires a one time configuration on travis-ci for the repo
on github by the owner of the repo.
