[shootout] handle default and cli input for k-nucleotide example
[shootout] handle default and cli input for k-nucleotide example

Quinny/perl6-examples,shlomif/perl6-examples,stmuk/perl6-examples,stmuk/perl6-examples,stmuk/perl6-examples,perl6/perl6-examples,Quinny/perl6-examples,perl6/perl6-examples,shlomif/perl6-examples,perl6/perl6-examples,shlomif/perl6-examples,stmuk/perl6-examples,perl6/perl6-examples,Quinny/perl6-examples,shlomif/perl6-examples,Quinny/perl6-examples,perl6/perl6-examples,Quinny/perl6-examples,shlomif/perl6-examples,stmuk/perl6-examples