* Load MIME data for these messages and parse, looking for a body either
in HTML or plain text or both
* If the MIME data had been trunctated and we can't find text, mark the
message as partially loaded and load the body text as we did before
(i.e. get the plain text body); this should be a rare case
TODO: Consider what is testable in the new EmailSyncAdapter code
Change-Id: I00a3066a373a0596431335593de356a4dda7f036
517c4f39b7