Unicode support.

[prataprc]

Default Scanner (SimpleScanner) and Terminal parser functions should have unicode support, along with utf8 encoding.

[prataprc]

While at it, add support for white spaces in unicode, for instance SimpleScanner.SkipWS().

[prataprc]

Skipping Unicode whitespace can be achieved by using SetWSPattern() API.
By setting the necessary whitespace unicode-points.

There is also unicode category called, Separator, Spaces
http://www.fileformat.info/info/unicode/category/Zs/list.htm

Can be used with golang's regexp \p{}: https://golang.org/pkg/regexp/syntax/