Factor out the need for a tag field in Files::AnalyzerArgs record.

This cleans up internals of how analyzer instances get identified by the
tag plus any args given to it and doesn't change script code a user
would write.

src/file_analysis/Analyzer.cc

@@ -0,0 +1,11 @@
+// See the file "COPYING" in the main distribution directory for copyright.
+
+#include "Analyzer.h"
+#include "Manager.h"
+
+file_analysis::Analyzer::~Analyzer()
+	{
+	DBG_LOG(DBG_FILE_ANALYSIS, "Destroy file analyzer %s",
+	        file_mgr->GetAnalyzerName(tag));
+	Unref(args);
+	}