Unify handling of errors in development project stage

In development stage if exception occurs (in render response)

1) HTML request + response not committed -> error page displayed
2) HTML request + response committed: -> "Response already committed " error in console + error page rendered as part or original view
3) AJAX request + response not committed -> <error> in XML response, javascript alert displayed
4) AJAX request + response committed -> Response already committed " error in console

Goal:

Provide same handling for all those cases. Ideally use same way as in 1) - error page. The 3) solution in development mode is useless - coder have to check XML response or/and console.