Custom WordPress install script - add to /wp-content/install.php before running the installer

install.php

<?php

/**
 * Creates the initial content for a newly-installed site.
 *
 * Adds sensible defaults for a new install
 *
 * @param int $user_id User ID.
 */

function wp_install_defaults( $user_id ) {

	/** Blog Description: "" **/
	update_option( 'blogdescription', '' );

	/** Mailserver: Clear content **/
	update_option( 'mailserver_url', '' );
	update_option( 'mailserver_login', '' );
	update_option( 'mailserver_pass', '' );
	update_option( 'mailserver_port', '' );

	/** Date format: "23rd November, 2014" */
	update_option( 'date_format', 'jS F, Y' );

	/** Time zone: "London" */
	update_option( 'timezone_string', 'Europe/London' );

	/** Permalink Structure **/
	update_option( 'permalink_structure', '/%postname%/' );

	/** Ping sites **/
	update_option( 'ping_sites', '' );
	
	/** Don't show the Welcome Panel **/
	update_user_meta( $user_id, 'show_welcome_panel', 0 );

	/** Set the default image link to none **/
	update_option( 'image_default_link_type', 'none' );

}