CA-140330: Use originator in session.login_with_password
-Calling new overload of the session.login_with_password() XAPI function (+originator field). This lets XenServer to group all sessions from a given XenCenter instance.

Signed-off-by: Gabor Apati-Nagy <gabor.apati-nagy@citrix.com>
Merge pull request #121 from GaborApatiNagy/login_originator_CA-140330

CA-140330: Use originator in session.login_with_password