Windows Roaming Client v1.3.8

Improved reachability test code to prevent race conditions
Implemented requests failure count that forces a network change check
Reduced DNS query timeout from 10000ms to 1980ms AND that value is divided by the number of configured servers
Changed failure count logic, now it does a reachability test followed by a network change check if needed (after 30 failed requests, it triggers a check)
Updated installer to NOT override modified files on update (e.g.: config file)