Heuristics for detection of Chrome on Windows; better error message if Chrome is not detected

The heuristics for detection of Chrome was only working on Linux. 
- Now there is a similar one for Windows;
- (Note though that in future we should try to detect the Chrome installation location);

Further, in case Chrome was not detected, the error message was essentially a NPE. :) Now this is a bit better in that it contains text instructing the user to place the chrome.location property in eclipse.ini etc. etc..