Better timeouting on installing tests

* Do not give a deadline for installing time. Instead, just raise a
  timeout expection, if the output is stalled for the timeout time.
  This value is optional and by default, it's the pexpect timeout time which
  is used (30s). We set for the installation progress case a 60s timeout for
  slow networks.
No need for --no-config in debian/rules anymore

* We don't output any debug info by default until a test fails.