CA-149027: Add Trim tests to xencert.

Signed-off-by: Siddharth Vinothkumar <siddharth.vinothkumar@citrix.com>
Reviewed-by: Chandrika Srinivasan <chandrika.srinivasan@citrix.com>
CA-149027: Update xencert-guide for space reclamation test.

Signed-off-by: Siddharth Vinothkumar <siddharth.vinothkumar@citrix.com>
Reviewed-by: Robert Breker <robert.breker@citrix.com>
CA-149027: Update verification form for space reclamation test.

Add optional space reclamation section to the test report.

Signed-off-by: Siddharth Vinothkumar <siddharth.vinothkumar@citrix.com>
Reviewed-by: Robert Breker <robert.breker@citrix.com>

GitHub: closes #34 on xenserver/xencert