Implement `rule { 'a' }`
Implement `Seq` rule combinator
Implement `FirstOf` rule combinator
Update copyright
Remove unnecessary deconstruction of char constant at CharRule
Add EOI. EOI is used instead of Option[Char]

Fix: rule is responsible for cursor manipulations, but not nextChar
Fix: EOI match is responsibility of CharRule but not of matchChar. So, matchChar is eliminated
Merge pull request #1 from alexander-myltsev/develop

First steps