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/policy/protocols/smtp/software.bro

@@ -43,10 +43,10 @@ export {
 	                   | /ZimbraWebClient/ &redef;
 }
 
-event smtp_data(c: connection, is_orig: bool, data: string) &priority=4
+event mime_one_header(c: connection, h: mime_header_rec) &priority=4
 	{
-	if ( c$smtp$current_header == "USER-AGENT" &&
-	     webmail_user_agents in c$smtp$user_agent )
+	if ( ! c?$smtp ) return;
+	if ( h$name == "USER-AGENT" && webmail_user_agents in c$smtp$user_agent )
 		c$smtp$is_webmail = T;
 	}