HevConfig: Bump up to 2.8.0.

Author: heiher

src/hev-config-const.h

@@ -11,7 +11,7 @@
 #define __HEV_CONFIG_CONST_H__
 
 #define MAJOR_VERSION (2)
-#define MINOR_VERSION (7)
+#define MINOR_VERSION (8)
 #define MICRO_VERSION (0)
 
 static const int UDP_BUF_SIZE = 1500;