delete attachment cache files if these are inline images.
The purpose of original logic of loadAttachmnet() is to keep
at most one attachment cache, probably to limit the size of
cached file. But it also purges all inline images.
Integrates CL 149551 from DocomoEmail.
BUG=1884385,1860250
Automated import of CL 149714
This extension is necessary to support some vendor specific
extended header, such as X-NoRtn-Addr of i-mode.net mail.
This change will update LocalStore database version to 24.
And it should be consistent between donutburger Email and DocomoEmail.
BUG=1741969
Automated import of CL 149328
deeper database-style operations with them. This enables two
new LocalStore APIs to be provided: A new version of
GetMessages() that can retrieve only flagged (or un-flagged)
messages, and a new method to set flags for an entire set of
messages, in a single SQL transaction.
BUG=1786939
Automated import of CL 147401
Jean-Baptiste Queru