Merge remote-tracking branch 'origin/topic/jsiwek/smtp-refactor'

- While updating, I did some further work on the branch.

- New function in the base/utils/files for extracting filenames
  from content-dispositions.

- New script for entity excerpt extraction if you aren't interested
  in full extraction.  The data goes a log field too.

- Some renaming and reorganization of types.

- Updated tests to work with new code.

* origin/topic/jsiwek/smtp-refactor:
  Make the doc.coverage test happy.
  SMTP script refactor. (addresses #509)

Conflicts:
	doc/scripts/DocSourcesList.cmake
	policy/protocols/smtp/__load__.bro
	policy/protocols/smtp/base/__load__.bro

scripts/base/utils/files.bro

@@ -12,4 +12,15 @@ function generate_extraction_filename(prefix: string, c: connection, suffix: str
 		conn_info = fmt("%s_%s", conn_info, suffix);
 		
 	return conn_info;
-	}
+	}
+	
+## For CONTENT-DISPOSITION headers, this function can be used to extract 
+## the filename.
+function extract_filename_from_content_disposition(data: string): string
+	{
+	local filename = sub(data, /^.*[fF][iI][lL][eE][nN][aA][mM][eE]=/, "");
+	# Remove quotes around the filename if they are there.
+	if ( /^\"/ in filename )
+		filename =  split_n(filename, /\"/, F, 2)[2];
+	return filename;
+	}