Merge branch 'ab/mediawiki-fixes'

Merge branch 'ab/mediawiki-fixes'

Modernization and fixes to MediaWiki remote backend.

* ab/mediawiki-fixes:
  remote-mediawiki: use "sh" to eliminate unquoted commands
  remote-mediawiki: annotate unquoted uses of run_git()
  remote-mediawiki: convert to quoted run_git() invocation
  remote-mediawiki: provide a list form of run_git()
  remote-mediawiki tests: annotate failing tests
  remote-mediawiki: fix duplicate revisions being imported
  remote-mediawiki tests: use CLI installer
  remote-mediawiki tests: use inline PerlIO for readability
  remote-mediawiki tests: replace deprecated Perl construct
  remote-mediawiki tests: use a more idiomatic dispatch table
  remote-mediawiki tests: use "$dir/" instead of "$dir."
  remote-mediawiki tests: change `[]` to `test`
  remote-mediawiki tests: use test_cmp in tests
  remote-mediawiki tests: use a 10 character password
  remote-mediawiki tests: use the login/password variables
  remote-mediawiki doc: don't hardcode Debian PHP versions
  remote-mediawiki doc: link to MediaWiki's current version
  remote-mediawiki doc: correct link to GitHub project