fix#540  This passes the study_id in the form

    when editing a study, instead of collecting it from the
    session. The study_id remains in the session so everything else
    functions the same.  It is just added to the form and used from
    the form when editing an existing study.
    I tested by selecting a study "emily_test" study_id 2114
    clicked on edit study
    opened a second tab and logged in
    selected study "emily_test_2" study_id 2134
    went back to the first tab and edited the study.
    Then I checked the database and the correct study was edited.