def file_diff(title, diff_data):
fd = {<EOL>'<STR_LIT>': '<STR_LIT>',<EOL>'<STR_LIT>': title,<EOL>'<STR_LIT>': diff_data,<EOL>}<EOL>return fd<EOL>
Builds a file diff element.  This element can be used to check whether
configuration files have changed or other similar checks.  Differences
will be highlighted when rendered via Javascript.

Args:
    title: The title to display
    diff_data: A dictionary of the form:
        { 'section_name' : { 'variable_name' : [diff, val_1, val_2] } }

Returns:
    A dictionary with the metadata specifying that it is to be
    rendered as a file diff element