Patch for Maximum Attachment size and Maximum Age

[Mike Dawson <mike@xxxxxxxxxxxxxxxxx>]

Dear All,

I have made a modification that allows for two new parameters that can 
be used on IMAP to IMAP syncs:

maxage - number of days to look back at email.  This I have found 
invaluable when starting with existing accounts on narrowband connections.
maxsize - maximum size of messages to download - e.g. to exclude large 
attachment (in bytes).

What would be the requirements to get this contribution included?  I 
have checked this out from Git - so I can easily push it that way.

If either parameter is present then an IMAP server side search will be 
executed to retrieve only those messages that match (this works out far 
faster than looking over a large account of years of mail for me).  So 
this should not effect / disable any existing functionality.

I would of course like to put this together for Maildir and Gmail - but 
this might take a few days to finish.  I guess it would be better just 
to push the final version when this is done?

Thanks,

-Mike