Issue #1425: Add 'unknown' to the list of valid typeof values
Treat leading slash as relative to the current dir for consistency with .gitignore

Signed-off-by: Anton Kovalyov <anton@kovalyov.net>
Issue #1453: Handle single-line comments for block ignore
No issue: tabs to spaces
No issue: tabs to spaces
No issue: tabs to spaces
Issue #1456: New option - nonbsp
No issue: change message for W104
Issue #1311: Add support for destructuring parameters (h/t arai-a)
Issue #1494: Add support for the Nashorn JavaScript engine
Issue #1494: Followup to add readFully as a global