MB-41209: Use specific 'Winsock2.h' header for timeval

When compiling under MSVC with 'WIN32_LEAN_AND_MEAN' defined (to avoid
symbol collisions with glog / reduce number of unnecessary headers
included), forestdb fails to compile with the following error:

    ..\forestdb\utils\gettimeofday_vs.cc(25): error C2027: use of undefined type 'timeval'
    forestdb\utils\gettimeofday_vs.h(17): note: see declaration of 'timeval'

The issue is that gettimeofday_vs.h & time_utils.h includes Windows.h,
which will only include the necessary header for 'timeval'
(Winsock2.h) if WIN32_LEAN_AND_MEAN is not defined.

Fix this by simply including the necessary Winsock2.h header directly.

Change-Id: I01338d47b2943e3646e959f19bf6118428ce0e4d
Reviewed-on: http://review.couchbase.org/c/forestdb/+/135517
Well-Formed: Build Bot <[email protected]>
Reviewed-by: Trond Norbye <[email protected]>
Tested-by: Build Bot <[email protected]>

Author: daverigby

utils/gettimeofday_vs.h

@@ -2,7 +2,7 @@
 #define _JSAHN_GETTIMEOFDAY_VS
 
 #include <time.h>
-#include <Windows.h>
+#include <Winsock2.h> // for timeval
 
 #ifdef __cplusplus
 extern "C" {

utils/time_utils.h

@@ -20,7 +20,7 @@
 
 #include <time.h>
 #if defined(WIN32) || defined(_WIN32)
-#include <Windows.h>
+#include <Winsock2.h> // for timeval
 #else
 #include <sys/time.h>
 #include <unistd.h>