Added admin init file
-set error/exception handler
-Create constants __SITE_PATH, __APPLICATION_PATH, __ADMIN_PATH, __CONFIG_PATH,__APPLICATION_PATH
-load OPC_Settings
-Set session handler
Added singelton for database connection
created OPC_Secure class for user login/auth
Added redirect common function
-changed admin.php to admin_init.php
-added login page and login view
-added check if user is loggedin in admin_init redirect to login when not