Description of problem:
When running a sealed Windows 7/7x64/8/8x64/2008/2008x64/2012x64 VM with sysprep floppy attached, all values provided from Run Once dialog are put in the sysprep file as plain-text, even when these Windows versions are using XML format for sysprep file, thus allowing to create a syntactically incorrect sysprep file.

Version-Release number of selected component (if applicable):
ovirt-engine-3.5.0-0.0.master.20140629172257.git0b16ed7.el6.noarch (beta)

How reproducible:
100%

Steps to Reproduce:
1. Have a "sealed" Windows VM, any of version 7, 7x64, 8, 8x64, 2008, 2008x64 or 2012x64
2. In Run Once dialog enter as the Admin Password value 'pass</word>'
3. Run the VM and watch the Windows initialization process

Actual results:
The Windows initialization fails on a parsing error of the unattend file.
If you check it (A:\sysprep.inf), you see the admin password is put in the XML as plain-text:

  <AdministratorPassword>
    <Value>pass</word></Value>
    <PlainText>true</PlainText>
  </AdministratorPassword>


Expected results:
For Windows versions using XML sysprep files, all special characters should be encoded, such as: in GUI enter value 'pass</word>' and in sysprep file will be value 'pass&lt;/word&gt;'.

Additional info: