A set of file analysis extensions.

- Enable manager to associate analyzers with a MIME type. With that,
  one can now say enable all analyzers for, e.g., "image/gif". This is
  exposed to script-land as

    Files::add_analyzers_for_mime_type(f: fa_file, mtype: string)

  For MIME types identified via libmagic, this happens automatically
  (via the file_new() handler in files/main.bro).

- Extend the analyzer API to better match that of protocol analyzers:

    - Adding unique analyzer IDs so that we can refer to instances
      from script-land.

    - Adding subtypes to Components so that a single analyzer
      implementation can support different types of analyzers
      internally.

    - Add an analyzer method SetTag() that allows to set the tag after
      construction.

    - Adding Init() and Done() methods for consistency with what other
      classes offer.

- Add debug logging to the file_analysis stream.

TODO: test cases missing for the new script-land functionality.

src/file_analysis/AnalyzerSet.cc

@@ -9,7 +9,10 @@ using namespace file_analysis;
 
 static void analyzer_del_func(void* v)
 	{
-	delete (file_analysis::Analyzer*) v;
+	file_analysis::Analyzer* a = (file_analysis::Analyzer*)v;
+
+	a->Done();
+	delete a;
 	}
 
 AnalyzerSet::AnalyzerSet(File* arg_file) : file(arg_file)
@@ -98,6 +101,7 @@ bool AnalyzerSet::AddMod::Perform(AnalyzerSet* set)
 		}
 
 	set->Insert(a, key);
+
 	return true;
 	}
 
@@ -124,7 +128,9 @@ bool AnalyzerSet::Remove(file_analysis::Tag tag, HashKey* key)
 	        file_mgr->GetComponentName(tag),
 	        file->GetID().c_str());
 
+	a->Done();
 	delete a;
+
 	return true;
 	}
 
@@ -176,6 +182,8 @@ void AnalyzerSet::Insert(file_analysis::Analyzer* a, HashKey* key)
 	        file_mgr->GetComponentName(a->Tag()), file->GetID().c_str());
 	analyzer_map.Insert(key, a);
 	delete key;
+
+	a->Init();
 	}
 
 void AnalyzerSet::DrainModifications()