Various forum fixes from 13.x - part 3 (process_inbound_mail fixes 1)
[bp/r52693][FIX] forums: Several fixes and improvements for process_inbound_mail for forums (was quite broken).
Use the html part if there's no text part available, and use the root 'body' section as a last resort (it's usually the source)
Ignore error report emails (needs more testing and possibly logging)
Try and find the message referred to in in-reply-to and use that topic if there is one
Also some code tidying and comments added 
[bp/r52694][FIX] forums: Restore mail in operation for feature_wiki_discuss.
Had been totally commented out as there was no feature or page_exists check - added them.

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@52749 b456876b-0849-0410-b77d-98878d47e9d5
Various forum fixes from 13.x - part 4 (process formatted mails)
[bp/r52714][ENH] forums: If using WYSIWYG use the html part in process_inbound_mail if available. Needs to be purified (before parsing to wiki if wysiwyg_htmltowiki) as email html can be messy 
[bp/r52733][FIX] forums: Make the recently added "parse html in incoming forum emails" optional with a new pref, as it often cannot cope with complicated table based html emails.

git-svn-id: file:///var/local/code.tiki.org/tikisvn/branches/12.x@52750 b456876b-0849-0410-b77d-98878d47e9d5