lots of changes; see description

- moved logging to file (#66)
- added preview updates KB4022168 and KB4022720 to supported updates in
installer script (untested)
- made adjustments to wix project (still WIP)
- moved shared globals to util.h

wufuc/dllmain.c

@@ -1,7 +1,6 @@
 #include <Windows.h>
 #include "core.h"
 #include "util.h"
-#include "shared.h"
 
 BOOL APIENTRY DllMain(HMODULE hModule, DWORD ul_reason_for_call, LPVOID lpReserved) {
     switch (ul_reason_for_call) {