This patch benefits from the better error message when key is missing
in config params. Instead of custom handling of missing param it
uses params[] directly.

I modified those params, where I was 100% certain that they are
required and doesn't have default value:
 * val = params.get(..) followed by if not val: raise...
 * int(params.get(...))
 * params.get(...).split()
 * commands which require string (eg. session.cmd(params.get(...)))

I didn't test all the tests before and after in order to verify
possible typos but I used pylint before and after, watching for
new errors (code rate before and after).
Signed-off-by: NLukáš Doktor <ldoktor@redhat.com>

In order to be consistent with previous changes.
Signed-off-by: NLucas Meneghel Rodrigues <lmr@redhat.com>

As part of our changes from kvm -> qemu.
Signed-off-by: NLucas Meneghel Rodrigues <lmr@redhat.com>

A frequent request we've got from users is that the name
'kvm' makes assumptions that are not true for a lot of
the use cases of the test suite. Then let's rename
the subtest 'kvm' to 'qemu', making it more accurate.
Signed-off-by: NLucas Meneghel Rodrigues <lmr@redhat.com>

All disk images, kernels and any file that will be
stored in the data dir should use the new data dir
reference.
Signed-off-by: NLucas Meneghel Rodrigues <lmr@redhat.com>

Signed-off-by: NLucas Meneghel Rodrigues <lmr@redhat.com>

Signed-off-by: NLucas Meneghel Rodrigues <lmr@redhat.com>