add program mutex, tray icon, portable install improvement

[ghost]

1. no use to run multiple, so add a program mutex to only allow one tallow :)
2. (close to) tray icon with a controlling menu and program option to control the behaviour
3. running portable now allows one to completely delete the program folder when done (sys file unlock)
   more comments in the code, you can remove them once/if pull is approved

[basil00]

Thanks for your efforts. I think the mutex and tray icon are good improvements. Uninstalling WinDivert is more tricky since this can interfere with other WinDivert applications that may be running on the system. I need to think about it.

[ghost]

on the portable uninstall/stop thing, just an idea

//this will only stop the service if it was initiated by the potable
//at_exit:
if (portable_install && installed_service_folder == tallow_fodler)
	stop_service();

the bad scenario: tallow run as portable & user has some other proggie using the service & user starts the other while tallow is active, tallow would send the stop leaving the other without service... or maybe check some WinDivert state change at start and exit of tallow? not familiar with it

[basil00]

Stopping the service will lead to problems, so best to remove this functionality. I think it may be possible to do safely using the REFLECT api and some undocumented features, but this should be done by the WinDivert runtime and not the application. I will look into it in future.