Changes in version 4.87:

• Update documentation for go mode.
• Update installation instructions and latexmk.cmd.
• Correct/improve some items in example_rcfiles/.
• Update detection of missing files reported by index package.
• Correct detection of .bbl and index files after change of aux_dir.
• Option --pdflatex no longer sets $pdflatex, so its behavior matches --lualatex etc.
• Removed banner options from on-line help; they are essentially obsolete.
• Correct some informational and warning messages.
• Add -cnf-line=STRING to set of allowed options passed to *latex.
• Correct method of detection of need for biber or bibtex: (In some cases, latexmk would incorrectly run bibtex and get an error, e.g., with beamer package and its option 'show only notes'.)