Fix compile errors with mingw64

Fix two errors:

win32.c:36:9: error: format '%s' expects argument of type 'char *', but argument 5 has type 'void **' [-Werror=format=]
         LOGE("%s: %s", s, msg);
         ^
and
win32.c:47:9: error: format '%ld' expects argument of type 'long int', but argument 4 has type 'int' [-Werror=format=]
         LOGE("ioctlsocket failed with error: %ld\n", iResult);
         ^
Fix a compile error with mingw64

Fix an error below.

json.c:135:42: error: cast from pointer to integer of different size [-Werror=pointer-to-int-cast]
                   (state, values_size + ((unsigned long) value->u.object.values), 0)) )
                                          ^
Merge pull request #59 from librehat/master

Fix mingw64 compiling errors