elifecleaner 0.74.0

Added: block.graphic_href_list(), collect a list of xlink:href values of graphic tags from the index_groups, based on existing code which can be reused
Removed / moved: fig.inf_file_identifier(), moved to utils.inf_file_identifier()
Modified: fig.inline_graphic_hrefs(), calls block.graphic_href_list(), will be fully compatible
Added: table.table_file_name(), from inf file name create a new table file name
Added: table.table_inline_graphic_hrefs(), get inline-graphic href values to be converted to <table-wrap>
Modified: table.transform_table_group(), will generate a new file name for a graphic file in a <table-wrap>
Added / moved: utils.inf_file_identifier(), moved from fig.inf_file_identifier()

Code merged in PR #177