refactoring, update ci build scripts, etc

- cache results of CompareWindowsVersion() to shared variables to cut
down on redundant calls
- apply appveyor build version to artifacts (wip, could be broken)
- add .gitattributes
- finish patternfind.c (snr funcs unused, untested)
- delete COPYING.txt (it is created from LICENSE during the build
process)

wufuc/dllmain.c

@@ -1,18 +1,19 @@
 #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) {
     case DLL_PROCESS_ATTACH:
     {
-        DisableThreadLibraryCalls(hModule);
-        if (WindowsVersionCompare(VER_EQUAL, 6, 1, 0, 0, VER_MAJORVERSION | VER_MINORVERSION)
-            || WindowsVersionCompare(VER_EQUAL, 6, 3, 0, 0, VER_MAJORVERSION | VER_MINORVERSION)) {
-
-            HANDLE hThread = CreateThread(NULL, 0, NewThreadProc, NULL, 0, NULL);
-            CloseHandle(hThread);
+        if (!IsOperatingSystemSupported(&g_IsWindows7, &g_IsWindows8Point1)) {
+            return FALSE;
         }
+
+        DisableThreadLibraryCalls(hModule);
+        HANDLE hThread = CreateThread(NULL, 0, NewThreadProc, NULL, 0, NULL);
+        CloseHandle(hThread);
         break;
     }
     case DLL_PROCESS_DETACH: