Update "Exercising the Services Locally" doc

The sample config used to have several drivers enabled, but this was changed
to default to the 'pxe_ipmitool' production driver. The developer documentation
for "Exercising the Services Locally", has examples using the 'fake_ipmitool'
driver. It won't work since only the pxe_ipmitool driver is available. This adds
instructions for updating the config file to enable fake_ipmitool instead of
pxe_ipmitool.

Users sometimes encounter the 'NodeLocked' exception while trying out the
sample "ironic" commands, due to the periodic sync_power_state task locking
the node. Documentation was added with instructions on how to turn off this
background sync_power_state task via a config setting.

Change-Id: Id53db08df59d13ca7a52505d6b3c0931551f4bf4

doc/source/dev/dev-quickstart.rst

@@ -129,9 +129,15 @@ created in the previous section to run everything else within::
     # disable auth since we are not running keystone here
     sed -i "s/#auth_strategy=keystone/auth_strategy=noauth/" etc/ironic/ironic.conf.local
 
+    # Use the 'fake_ipmitool' test driver
+    sed -i "s/#enabled_drivers=pxe_ipmitool/enabled_drivers=fake_ipmitool/" etc/ironic/ironic.conf.local
+
     # set a fake host name [useful if you want to test multiple services on the same host]
     sed -i "s/#host=.*/host=test-host/" etc/ironic/ironic.conf.local
 
+    # turn off the periodic sync_power_state task, to avoid getting NodeLocked exceptions
+    sed -i "s/#sync_power_state_interval=60/sync_power_state_interval=-1/" etc/ironic/ironic.conf.local
+
     # initialize the ironic database
     # this defaults to storing data in ./ironic/ironic.sqlite