Split version into separate include fio

Include it from the Windows version file, at least we only have
to update the version in two places now instead of three.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
diff --git a/server.c b/server.c
index 61bbe44..c3502cd 100644
--- a/server.c
+++ b/server.c
@@ -22,6 +22,8 @@
 #include "crc/crc16.h"
 #include "ieee754.h"
 
+#include "fio_version.h"
+
 int fio_net_port = 8765;
 
 int exit_backend = 0;