Win32 tests and timeout fix (#776)

Unit tests in Windows and a Windows timeout fix

This commit gets our unit tests compiling and running on Windows as well as removes a duplicated `timeval` -> `DWORD` conversion logic in sockcompat.c 

There are minor differences in behavior between Linux and Windows to note:

1.  In Windows, opening a non-existent hangs forever in WSAPoll whereas
    it correctly returns with a "Connection refused" error on Linux.
    For that reason, I simply skip this test in Windows.

    It may be related to this known issue:
    https://daniel.haxx.se/blog/2012/10/10/wsapoll-is-broken/

2.  Timeouts are handled slightly differently in Windows and Linux.  
    In Linux, we intentionally set REDIS_ERR_IO for connection
    timeouts whereas in Windows we set REDIS_ERR_TIMEOUT.  It may be
    prudent to fix this discrepancy although there are almost certainly
    users relying on the current behavior.

1 files changed, 1 insertions, 5 deletions

diff --git a/net.c b/net.c
index c928b33..bdb8943 100644
--- a/net.c
+++ b/net.c
@@ -316,11 +316,7 @@ int redisCheckSocketError(redisContext *c) {
 int redisContextSetTimeout(redisContext *c, const struct timeval tv) {
     const void *to_ptr = &tv;
     size_t to_sz = sizeof(tv);
-#ifdef _WIN32
-    DWORD timeout_msec = tv.tv_sec * 1000 + tv.tv_usec / 1000;
-    to_ptr = &timeout_msec;
-    to_sz = sizeof(timeout_msec);
-#endif
+
     if (setsockopt(c->fd,SOL_SOCKET,SO_RCVTIMEO,to_ptr,to_sz) == -1) {
         __redisSetErrorFromErrno(c,REDIS_ERR_IO,"setsockopt(SO_RCVTIMEO)");
         return REDIS_ERR;