Add ConnectionDefinition, remove ConnectionOptions

[olvlvl]

Currently PDO parameters are still defined using magic strings: dsn, username, and password. We should add a class to use proper constants, and include connection options too:

<?php

namespace ICanBoogie\ActiveRecord;

interface ConnectionDefinition
{
	/**
	 * The Data Source Name.
	 */
	const DSN = 'dsn';
	
	/**
	 * The user name for the DSN string. This parameter is optional for some PDO drivers. 
	 */
	const USERNAME = 'username';
	
	/**
	 * The password for the DSN string. This parameter is optional for some PDO drivers.
	 */
	const PASSWORD = 'password';
	
	/**
	 * A key=>value array of driver-specific connection options.
	 */
	const DRIVER_OPTIONS = 'driver_options';

	/**
	 * Connection identifier.
	 */
	const OPTION_ID = '#id';

	/**
	 * Charset and collate.
	 *
	 * Default: {@link DEFAULT_CHARSET_AND_COLLATE}.
	 */
	const OPTION_CHARSET_AND_COLLATE = '#charset_and_collate';

	/**
	 * Table name prefix.
	 */
	const OPTION_TABLE_NAME_PREFIX = '#table_name_prefix';

	/**
	 * Time zone offset used for the connection.
	 *
	 * Default: {@link DEFAULT_TIMEZONE}.
	 */
	const OPTION_TIMEZONE = '#timezone';
	
	/**
	 * Default user name.
	 */
	const DEFAULT_USERNAME = 'root';
	
	/**
	 * Default password.
	 */
	const DEFAULT_PASSWORD = null;
	
	/**
	 * Default driver options.
	 */
	const DEFAULT_DRIVER_OPTIONS = [];

	/**
	 * Default charset.
	 */
	const DEFAULT_OPTION_CHARSET = 'utf8';

	/**
	 * Default collate.
	 */
	const DEFAULT_OPTION_COLLATE = 'utf8_general_ci';

	/**
	 * Default value for {@link CHARSET_AND_COLLATE}.
	 */
	const DEFAULT_OPTION_CHARSET_AND_COLLATE = "utf8/general_ci";

	/**
	 * Default value for {@link DEFAULT_TABLE_NAME_PREFIX}.
	 */
	const DEFAULT_OPTION_TABLE_NAME_PREFIX = '';

	/**
	 * Default value for {@link TIMEZONE}.
	 */
	const DEFAULT_OPTION_TIMEZONE = '+00:00';
}