[exim] demime => MIME ACL equivalent

The spec says the old demime provides no additional facilities over the
MIME ACL, but I am unable to find the equivalent for the following old
demime acl condition:

deny message   = This message contains a MIME error ($demime_reason)
      demime    = *
      condition = ${if >{$demime_errorlevel}{2}{1}{0}}

Even with using several functions in the MIME ACL, the old demime still
catches a handful of these:

rejected after DATA: This message contains a MIME error (demime acl
condition: line length in message or single header size exceeds 131071
bytes)


Thanks,

-Mike