Move binpac code into the main Zeek repository

This is based on commit 48f75b5f6415fe9d597e3e991cec635b1bc400dc from
the binpac repository.

tools/binpac/src/pac_output.h

@@ -0,0 +1,40 @@
+#ifndef pac_output_h
+#define pac_output_h
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <string>
+
+using namespace std;
+
+class OutputException {
+public:
+    OutputException(const char* arg_msg);
+    ~OutputException();
+    const char* errmsg() const { return msg.c_str(); }
+
+protected:
+    string msg;
+};
+
+class Output {
+public:
+    Output(string filename);
+    ~Output();
+
+    int println(const char* fmt, ...);
+    int print(const char* fmt, ...);
+
+    int indent() const { return indent_; }
+
+    void inc_indent() { ++indent_; }
+    void dec_indent() { --indent_; }
+
+protected:
+    int print(const char* fmt, va_list ap);
+
+    FILE* fp;
+    int indent_;
+};
+
+#endif /* pac_output_h */