Move the tokenizer code into libpkg
Allow arguments in ucl keywords

if ucl keyword defines the boolean "arguments" then %@ will be parsed
and splitted:
%# == number of arguments
%@ == unsplitted string
%1 == first argument
%2 == second argument

In the action field it is possible to specify which of the splitted
arguments will be used the following way:

actions: [file(1)]