Implement and test InternetTime{From,To}SystemTime{A,W}.
Correct spelling in InternetCheckConnectionA.

diff --git a/include/wininet.h b/include/wininet.h
index 9fcf4d9..ed5cb5c 100644
--- a/include/wininet.h
+++ b/include/wininet.h
@@ -285,6 +285,7 @@
 BOOLAPI InternetTimeFromSystemTimeW(CONST SYSTEMTIME *,DWORD ,LPWSTR ,DWORD);
 #define InternetTimeFromSystemTime WINELIB_NAME_AW(InternetTimeFromSystemTime)
 
+#define INTERNET_RFC1123_FORMAT    0
 #define INTERNET_RFC1123_BUFSIZE   30
 
 BOOLAPI InternetTimeToSystemTimeA(LPCSTR ,SYSTEMTIME *,DWORD);