bifcl: Move headers into include/ subdir

This avoids potential problems with libc++ 8+ on case-insensitive file
systems due to inclusion of a new header called <version> which will end
up conflicting with the VERSION file if the search path includes the
project root.

tools/bifcl/include/module_util.h

@@ -0,0 +1,17 @@
+//
+// These functions are used by both Zeek and bifcl.
+//
+
+#include <string>
+
+using namespace std;
+
+static const char* GLOBAL_MODULE_NAME = "GLOBAL";
+
+extern string extract_module_name(const char* name);
+extern string extract_var_name(const char* name);
+extern string normalized_module_name(const char* module_name); // w/o ::
+
+// Concatenates module_name::var_name unless var_name is already fully
+// qualified, in which case it is returned unmodified.
+extern string make_full_var_name(const char* module_name, const char* var_name);