Fixes for script auto-documentation.

- Fixing the parts of the `make restdoc` and `make doc` process that were
  broken by the last Bro script re-organization

- Generated documentation for Bro scripts derived from BiFs now use the
  original BiF source file as the "original source file" link

- Renaming of the internal POLICYDEST definition and other misc places that
  refer to "policy" scripts; that terminology doesn't make total sense now

- Added a documentation blacklist reminder test that will fail if there's
  scripts that are blacklisted from being documentated because they're still
  in progress

- Some minor Bro script changes to fix small @load dependency errors

Addresses #543

src/BroDoc.h

@@ -24,10 +24,9 @@ public:
 	 * If the filename doesn't end in ".bro", then ".rst" is just appended.
 	 * Any '/' characters in the reST file name that result from choice of
 	 * the 'rel' parameter are replaced with '^'.
-	 * @param subpath A string representing a subpath of BROPATH's policy/
-	 *        directory in which the source file is located.  It can
-	 *        also be full path to the file or a full path that's in BROPATH,
-	 *        but in either of those cases, the parameter is essentially
+	 * @param rel A string representing a subpath of the root Bro script
+	 *        source/install directory in which the source file is located.
+	 *        It can also be an absolute path, but then the parameter is
 	 *        ignored and the document title is just derived from file name
 	 * @param abs The absolute path to the Bro script for which to generate
 	 *        documentation.
@@ -211,6 +210,7 @@ protected:
 	FILE* reST_file;
 	std::string reST_filename;
 	std::string source_filename;	// points to the basename of source file
+	std::string downloadable_filename; // file that will be linked for download
 	std::string doc_title;
 	std::string packet_filter;