tests: daemon-conf: accommodate numeric-valued config params

tests: daemon-conf: accommodate numeric-valued config params

This test would hang when failing to perturb the soon-to-be-
added numeric (and non-boolean) valued parameters, max_clients,
max_workers, min_workers.
* tests/daemon-conf: Require that all commented-out settings
in libvirtd.conf have the same form.  Before, two parameters
were not being tested, since a space had snuck between the
leading "#" and the "param = value" parts.
Apply each RHS-value-perturbing transformation
separately, not in series.
Let VERBOSE=yes turn on debugging.
Be more verbose by default, since this is a relatively
long-running test.
* qemud/libvirtd.conf: Normalize the spacing around each setting
that is to be perturbed by tests/daemon-conf.