Main section [filehighlight] contain key names as highlight groups and values as color pairs
color pair described as 'foreground;background'. 'background' may be omited.

other sections describe filegroup of highlight.
Keys in these groups:

type
    - file type. if present, all other option ignored;
regexp
    - regular expression. If present, 'extensions' option ignored;
extensions
    - list of extensions of files. Separated by ';' sign.

'type' key may have values:

- FILE - all files.
  - FILE_EXE
- DIR - all directoryes
  - LINK_DIR
- LINK (all links except stale link)
  - HARDLINK
  - SYMLINK
- STALE_LINK
- DEVICE (all device files)
  - DEVICE_BLOCK
  - DEVICE_CHAR
- SPECIAL (all special files)
  - SPECIAL_SOCKET
  - SPECIAL_FIFO
  - SPECIAL_DOOR
