port context user guide.
port context user guide.

dropped most of the documentation. was SU/SE specific and had no value
any longer. added TBW paragraphs for sections that have to be written.

openengsb/openengsb,openengsb/openengsb,openengsb/openengsb,openengsb/openengsb,openengsb/openengsb,openengsb/openengsb