ValExtLinks: Changed --skip-archive-links argument to --check-archive-links because the default should be to skip them. Val now uploads all three formats of its report, and links to the RTF and TXT versions from the HTML one. Val can also now tell whether each upload succeeded. A report with no link issues will print a placeholder message in that section of the report. Fixed a bug where Val thought a link should be an interwiki link when it was really a link to an archive.org snapshot from said wiki.