- xenserver module_util: fixed a bug in gather_vm_params function where
an exception was generated if XenServer product_version_text_short
parameter contained non numeric characters, e.g. "7.1 CU1" on
XenServer version 7.1 with Cummulative Update 1. Code was changed
to use product_version parameter instead which is all numeric.
- xenserver module_util: get_xenserver_version function is changed
to return a list of integers for major, minor and update version
instead of list of strings.
- xenserver module_util: unit tests are updated according to changes.
- xenserver module_util: removed unused imports.
