Misc. doc/script/test cleanup.

- fixing some Metrics::add_data() call signatures
- slight refactors to cluster framework @if and adding a NONE NodeType for
  so local_node_type() will return that instead of just emitting an error
  when cluster mode isn't enabled
- `make restdoc` target now uses bro's bare-mode
- bro scripts generated from bifs now really only live in the build/src/base/
  directory and changed the DocSourcesList.cmake to dynamically figure out
  what bifs exist by looking in src/ instead of build/src/
- add some missing @load dependencies

src/BroDoc.cc

@@ -60,7 +60,7 @@ BroDoc::BroDoc(const std::string& rel, const std::string& abs)
 	if ( ! reST_file )
 		fprintf(stderr, "Failed to open %s\n", reST_filename.c_str());
 
-#ifdef DEBUG
+#ifdef DOCDEBUG
 	fprintf(stdout, "Documenting absolute source: %s\n", abs.c_str());
 	fprintf(stdout, "\trelative dir: %s\n", rel.c_str());
 	fprintf(stdout, "\tdoc title: %s\n", doc_title.c_str());