[feature] move options page under Settings

[StefanoCecere]

i think it's too much to have the settings page in the main menu..

what about putting it under the Settings?

just change

    add_menu_page('EBS Settings', ' EBS Settings', 'manage_options', 'ebs/ebs-settings.php', 'osc_ebs_setting_page', plugins_url('/images/icon.png', __FILE__));

to

    add_options_page('EBS Settings', ' EBS Settings', 'manage_options', 'ebs/ebs-settings.php', 'osc_ebs_setting_page', plugins_url('/images/icon.png', __FILE__));