1 Main section [filehighlight] contain key names as highlight groups and values as color pairs
2 color pair described as 'foreground;background'. 'background' may be omited.
4 other sections describe filegroup of highlight.
8 - file type. if present, all other option ignored;
10 - regular expression. If present, 'extensions' option ignored;
12 - list of extensions of files. Separated by ';' sign.
14 'type' key may have values:
18 - DIR - all directoryes
20 - LINK (all links except stale link)
24 - DEVICE (all device files)
27 - SPECIAL (all special files)