Add field 'exception_type' to 'Incident'.

Signed-off-by: Dhananjay Nakrani <dhananjaynakrani@gmail.com>
Make server accept php error incidents.

Signed-off-by: Dhananjay Nakrani <dhananjaynakrani@gmail.com>
Add backward compatibility. Server now accepts incidents even if 'exception_type' is not set (case for older versions of PMA). It considers such incidents to be 'js' errors.

Signed-off-by: Dhananjay Nakrani <dhananjaynakrani@gmail.com>