Removed buggy exception error handler

`set_exception_handler` expects a function that takes exception as a single argument (see http://php.net/manual/en/function.set-exception-handler.php).

Setting `handleError` as exception handler produces the following error:
 `PHP Fatal error:  Uncaught exception 'ErrorException' with message 'Missing argument 2 for Codeception\Subscriber\ErrorHandler::errorHandler()' in /some/path/codeception/codeception/src/Codeception/Subscriber/ErrorHandler.php:31`
Merge pull request #1096 from Entea/patch-2

Removed buggy exception error handler
updated element not found webdriver exceptions for webdriver v0.4
Merge branch '1.8' of github.com:Codeception/Codeception into 1.8
Make WebDriver config docs match actual config values

There seems to be a bit of variation (across versions/branches) between what the doc says regarding defaults and what is set as defaults - but one thing is consistent - that the doc doesn't match the config being utilized.
Merge pull request #1141 from PrplHaz4/1.8

Make WebDriver config docs match actual config values