add iometer test for Windows guest

Iometer is an I/O subsystem measurement and characterization
tool for single and clustered systems. We use it to test block I/O
performance of virtual machine.

Need to add some util files to winutils.iso/Iometer:
 http://kongove.fedorapeople.org/autotest/Iometer.tar.gz

This patch just added the testcase, I will change this case to generate
RHS format result, then we can use regression.py to compare the results.

Signed-off-by: Amos Kong <akong@redhat.com>