Reverts the patch series about console wrappers

This reverts commits 030a9cb8 and
ae082df0.

There are two problems:

- Makefile.am breakage, which is trivial to revert
- unittest breakage, which honestly I'm not sure how to fix and how
  serial consoles interact with the unpause helper

After the reset, the startup --paused still works but won't unpause
the instance automatically (if I understood the code correctly).

Furthermore, the code also fixes a style issue in hv_kvm.py (too long
line) introduced by the next commit after the above two.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>