MyNP: MySQL database access wrapper using MySQLi

This class is a MySQL database access wrapper using the MySQLi extension. It can:

- Establish database connections
- Execute SQL queries to retrieve a single value, a single row or multiple rows in a single array
- Encode query values of different types for use in queries
- Retrieve the identifier in the last inserted record
- Retrieve the number of rows affected by a query
- Compose INSERT, UPDATE and DELETE queries from lists of parameters that define tables, fields, field values and condition clauses

The code and comments are in Spanish.