Logger: some status messages

[carloscs]

After utorrent starts, the log only shows "[date] uTorrent Initializing..."

Add two messages to inital log:

[date] uTorrent finished initialization.

[date] Logging is disabled - right mouse click->Choose Peer Traffic to enable.

Also:

When the user starts logging write a message 'Logging started'.

When the user stops logging write a message 'Logging stopped'.