insert a summary of host hardware infomation

This patch relies on some sysinfo files that are added in pull request 808 [1]
[1] https://github.com/autotest/autotest/pull/808

example:
<pre>

Machine Info:
o CPUs(8 * ['Intel(R) Core(TM) i7-3520M CPU @ 2.90GHz']), Cores(2), Threads(4), Sockets(1),
o NumaNodes(1), Memory(15.4G), NICs(2)
o Disks(['/dev/sda: 238.5 GiB'] | ['sda1', 'sda2'])

Please check sysinfo directory in autotest result to get more details.
(eg: http://autotest-server.com/results/5057-autotest/host1/sysinfo/)

</pre>