Some of the existing E_ERROR conditions have been
   converted to something that can be caught with a user-defined error
   handler.  If an E_RECOVERABLE_ERROR
   is not handled, it will behave in the same way as
   E_ERROR behaves in all versions of PHP.  Errors of
   this type are logged as Catchable fatal error.
  
   This change means that the value of the E_ALL
   error_reporting constant is 
   now 6143, where the previous value was 2047. Because PHP constants have 
   no meaning outside of PHP, in some cases the integer value is used 
   instead so these will need to be adjusted. So for example by
   setting the error_reporting mode from either the
   httpd.conf or the
   .htaccess files, the value has to be changed
   accordingly.  The same applies when the numeric values are used
   rather than the constants in PHP scripts.
  
   As a side-effect of a change made to prevent duplicate error messages when
   track_errors is
   On, it is now necessary to return FALSE from
   user defined error handlers in order to populate
   $php_errormsg.  This
   provides a fine-grain control over the levels of messages stored.