Command line option to specify serial for generating BINK1998 keys (#33)

* specify pre-set serial on CLI for BINK1998

* fix CLI::printID

src/header.h

@@ -89,6 +89,8 @@ struct Options {
     std::string instid;
     std::string keyToCheck;
     int channelID;
+    bool serialSet;
+    int serial;
     int numKeys;
     bool verbose;
     bool help;