[latexmk/f15] Add latexmk.pdf to docs. Update to 4.30a: - Fix use of bibtex when $aux_dir and/or $out_dir are set.

[Jerry James]

Summary of changes:

  cb19c08... Add latexmk.pdf to docs. Update to 4.30a: - Fix use of bibt (*)

(*) This commit already existed in another branch; no separate mail sent