Integrate Excavator API: $ActiveMiner.LogFile not updated on algo switch
as per title.

Scenario:
Excavator starts for the first time (e.g. with algo neoscrypt)
-> $ActiveMiner{neoscrypt }.LogFile get set OK 

After some time MPM switches Excavator algo  (e.g. to pascal)
->$ActiveMiner{pascal}.LogFile remains $null

Question: Should $ActiveMiner{neoscrypt}.Logfile get cleared?
