sdk: aligning API initialization with iso-uploader

Aligning API initialization method with iso-uploader.
This includes:
- fixed creating objects in an insecure way
- align imageuploader.conf with isouploader.conf
- align sdk version requirement

Excludes:
- add the nossl option for the engine connection
(doesn't work correctly)

Change-Id: I59e9d95cd76a961265acc5475be6db7843b75121
Related-To: http://gerrit.ovirt.org/9288
Related-To: http://gerrit.ovirt.org/10815
Bug-Url: https://bugzilla.redhat.com/951100
Signed-off-by: Alex Lourie <alourie@redhat.com>
Signed-off-by: Sandro Bonazzola <sbonazzo@redhat.com>