ui: Host settings not populated with prtocol info on Guide Me panels

DataCenter and Cluster Guide me panels did not set protocol type so it
was always set to xmlrpc unless user changed the value.

Bug-Url: https://bugzilla.redhat.com/1142706
Change-Id: I2308aa387b584388ecb5f44cfb0973380688eff1
Signed-off-by: pkliczewski <piotr.kliczewski@gmail.com>
core: jsonrpc only for 3.5 cluster compatibility level

When cluster level is set to lower level than 3.5 we must not let people
change default xmlrpc to jsonrpc. Lower versions of vdsm are not able to
understand jsonrpc so we disabled possibility on the UI.


Bug-Url: https://bugzilla.redhat.com/1142945
Change-Id: Ifaf0afa2abbd6ccc40a4fd84bebcb94544271639
Signed-off-by: pkliczewski <piotr.kliczewski@gmail.com>