Patch and pack mechanism changed on Ely (XS 7.1)

[olivierlambert]

Supplemental packs are not detected the same way: they are now "merged" with patches, but they also changed the field.

• patches field is deprecated
• Patches are now in host.updates (pointing to a update UUID which is the installed patch)
• Packs are now in host.updates (pointing to a update UUID which is the installed pack)

Details here:

• https://github.com/xenserver/xenadmin/blob/06e624c3dc825b11b0cb95bc60eb2dd8443ca83f/XenAdmin/TabPages/GeneralTabPage.cs#L1673
• https://github.com/xenserver/xenadmin/blob/06e624c3dc825b11b0cb95bc60eb2dd8443ca83f/XenAdmin/TabPages/GeneralTabPage.cs#L1725

Consequences:

• it messes with the pack check for XOSAN (doesn't work for 7.1)
• patch install seems to be broken on 7.1 too it's now the same mechanism than pack install!
• detection if a host need reboot can be done now with host.updates_requiring_reboot which returns a list of patches that requires reboot (so if there is one record here, the host need a reboot)