Calling jenkins job builder with no config file

[mkluson]

I come with better solution for issue #41. Instead of injecting password to all
jobs, which update or create some other job, I change the way how xml for
updating/creating job is obtained from source yaml file.

In case jekins job builder does not need access to Jenkins instance, it is called
without any config file.

[optak]

I consulted this patch with Martin today and I would recommend it for merge.
It can fix build-on-commit use case.
If not, well,... it's broken already and nobody except from baseos-qe uses it, so the risk of regression is minimal.