virttest: Update khugepaged test timeout

As the khugepaged process will quit slowly in some OS, enlarge the
timeout for khugepaged test from 5s to 50s. And also use the method that
check process status in a while loop which will break when the khugepaged
process status is changed as expect instead of time.sleep(timeout).

Signed-off-by: Yiqiao Pu <ypu@redhat.com>
virttest: Record the output from QMP monitor when failed to get the greeting message

Record the json output from QMP monitor when we raise the MonitorProtocolError. It
may help us to analyse what failed this step.

Signed-off-by: Yiqiao Pu <ypu@redhat.com>
Modifying spice cfg file to use nettype = bridge
Merge pull request #1068 from ypu/thp

virttest: Update khugepaged test timeout
Merge pull request #1078 from ypu/qmp

virttest: Record the output from QMP monitor when failed to get the gree...
virttest.libvirt_vm: Raise stderr of virsh.start after starting failed.

Signed-off-by: Yu Mingfei <yumingfei@cn.fujitsu.com>
Merge pull request #1085 from swapnakrishnan2k/add_nettype_bridge

Modifying spice cfg file to use nettype = bridge
virttest.libvirt_xml.pool_xml: Fix py 2.4 incompatible construct

Signed-off-by: Lucas Meneghel Rodrigues <lmr@redhat.com>
Merge branch 'next' of https://github.com/autotest/virt-test into next