Support namespaces / modules in bif. Checkpoint.

This change is actually two-fold:
a) bif's now accept module XYZ; statements and module::ID for
   function, const, event, enum, etc. declartation
b) Added C++-namespaces to variables, functions, etc. that are declared
   in bif but accessed from C++
   This required some (lightweight) re-factoring of the C++ codes.
   Note, event's don't have their own C++ namespace yet, since this
   would require a rather huge re-factoring.

Compiles and passes test suite.
New namespace feature not tested yet.
Documentation to follow.

src/module_util.cc

@@ -0,0 +1,65 @@
+//
+// See the file "COPYING" in the main distribution directory for copyright.
+
+#include <string>
+#include <string.h>
+#include "module_util.h"
+
+static int streq(const char* s1, const char* s2)
+	{
+	return ! strcmp(s1, s2);
+	}
+
+// Returns it without trailing "::".
+string extract_module_name(const char* name)
+	{
+	string module_name = name;
+	string::size_type pos = module_name.rfind("::");
+
+	if ( pos == string::npos )
+		return string(GLOBAL_MODULE_NAME);
+
+	module_name.erase(pos);
+
+	return module_name;
+	}
+
+string extract_var_name(const char *name)
+	{
+	string var_name = name;
+	string::size_type pos = var_name.rfind("::");
+
+	if ( pos == string::npos )
+		return var_name;
+
+	if ( pos + 2 > var_name.size() )
+		return string("");
+
+	return var_name.substr(pos+2);
+	}
+	
+
+
+string normalized_module_name(const char* module_name)
+	{
+	int mod_len;
+	if ( (mod_len = strlen(module_name)) >= 2 &&
+	     streq(module_name + mod_len - 2, "::") )
+		mod_len -= 2;
+
+	return string(module_name, mod_len);
+	}
+
+string make_full_var_name(const char* module_name, const char* var_name)
+	{
+	if ( ! module_name || streq(module_name, GLOBAL_MODULE_NAME) ||
+	     strstr(var_name, "::") )
+		return string(var_name);
+
+	string full_name = normalized_module_name(module_name);
+	full_name += "::";
+	full_name += var_name;
+
+	return full_name;
+	}
+