By Tim Hepher LONDON (Reuters) -Airbus and Qatar Airways skirmished on Friday over relations with aviation watchdogs and a deluge of confidential documents as legal claims over grounded jets hit $2 billion. Filling a large courtroom in the London High Court, the latest procedural hearing in a high-stakes contractual and safety dispute laboured over the intricate details of “shared drives” and “search terms” as each side looked for a smoking gun showing cosy relations with regulators. “A short-cut ought to be taken,” Judge David Waksman said after sometimes testy arguments about how to handle m…