Add detection for XML support on Windows
Make Error.stack returns a string to match Node.js
Fix compile error introduced by 2262df1c87dec4a05e7399cd9680.

The signature of ChromeClient::addMessageToConsole was changed but not
adapted in the WK2 code branch.

Change-Id: I2cc1abf56b1b3c011199cd861e9d6d1f4e125ac9