0.20.0

Breaking changes:

• luacheck now exits with 2 instead of 1 if there are syntax errors
  or invalid inline options present. It now exits with 3 instead of
  2 if I/O errors are present. It now exits with 4 instead of 3
  on a critical error (#94).

New features and improvements:

• If project-specific .luacheckrc is not found, luacheck will now use
  config from some global location if it is present there. Default global
  location is %LOCALAPPDATA%\Luacheck\.luacheckrc on Windows,
  ~/Library/Application Support/Luacheck/.luacheckrc on OS X/macOS, and
  $XDG_CONFIG_HOME/luacheck/.luacheckrc or ~/.config/luacheck/.luacheckrc
  on other systems. This behaviour can be tweaked with --default-config and
  --no-default-config options (#102).
• New --[no-]max-code-line-length, --[no-]max-string-line-length,
  --[no-]max-comment-line-length CLI options and corresponding
  config and inline options that limit line length only for subsets of lines
  based on line type: string lines have their line endings within a string,
  comment lines have their line endings within a comment, other lines
  are code lines (#100).
• New love std set containing globals added by Love2D framework (#108).
• For warnings about unused values and fields, if the value is always
  overwritten by a single other value, location of the overwriting
  assignment is mentioned in the warning message (#106).
• When attempting to check a directory while LuaFileSystem is not installed,
  luacheck now mentions that LuaFileSystem is required in the error
  message (#103).
• Improved warning message for unbalanced assignment warnings (#104).