renamed VerbalPredicate to Phraser, thus eliminating all collisions
with the meaning of Predicate used by Guava.
renamed predicate() to verb();
created an implementation of Phraser; types of generics (such as
Verb/Verb2, etc) are not stable/tight yet, except fluctuations
renamed UnaryComplements to AtomicUnaryComplements;
added AtomicUnaryRoles, an implementation of both Role and Roles;
added UnaryPhraser;
added a static Role object named subject into Role.java
renamed Subject to SubjectComplement (to distinguish from the Role one)
simplified the construction of the subject role;
added arguments check;
referenced Role.subject from Roles.subject
Improved ArrayComplements (it was all wrong).
Other changes to Role and Preposition (what?)
refactored AtomicComplement from interface to class
renamed ArrayComplements to ComplementsOnArrayList and removed
superclass ComplementsOnCollection
CompositePhrase declares two types but then it doesn't use them!
Created two alternative interfaces that obviate this
obsoleted PrepositionalPhrase; removed asString() from Preposition
added phrase(Entity ent) in UnaryPhraser; to do so, had to make 
implementations of Complement a subtype of Complements by adding
and arity() and asComplements() methods to them