Prova v2.3.0

• Introduced the much faster mutualinfoF() for variates with finite domains.
• Introduced the function exputility() for the calculation of expected utilities and their revisability, together with plot() and print() methods.
• Changed the name of the internal S3 classes to avoid clashes with other packages.
• Improved plot labels.
• Updated and corrected documentation.
• Updated introductory vignette.
• Simplified omission of arguments like Y =, X =, K =.