travis: Do a distcheck in our travis CI build

Allows us to catch even more issues

Closes #447
Reviewed-by: Marius Vollmer <marius.vollmer@redhat.com>
Remove last traces of libtool from our build and tests

We got rid of libtool usage a while back, remove some last vestiges
which were breaking our check-memory target if libtool wasn't installed
and other little bits.
Don't run test-server phantomjs tests under valgrind
Run 'check-memory' and 'distcheck targets in travis as well

This allows us to catch various memory related problems
although, not leaks (yet). Also files not distributed properly
or cleaned up properly.
tools: Make tap-gtester more compatible with older python

The argparse in older python seems to behave differently
with regards to the '--' argument so use argparse.REMAINDER
to catch the command line.