rename dupkt -> dupkt_filter

src/CMakeLists.txt

@@ -1,6 +1,6 @@
 add_subdirectory(timestamp)
 add_subdirectory(tuple)
 add_subdirectory(packet)
-add_subdirectory(dupkt)
+add_subdirectory(dupkt_filter)
 add_subdirectory(session)
 add_subdirectory(stellar)

src/dupkt_filter/dupkt_filter.h

@@ -6,6 +6,8 @@ extern "C"
 {
 #endif
 
+// Duplicated Packet Filter for IPv4-based TCP Packet
+
 #include "packet.h"
 
 struct dupkt_filter *dupkt_filter_create(uint8_t enable, unsigned int capacity, double error_rate, int timeout_s);