www: link to the updated Windows build
SVN_SILENT made messages (.desktop file)
Fix minor typo
Fix extracting attachment filename from the oboslete "name" Content-Type parameter

Thanks to andyjpb on IRC for reporting.

v2: Let an empty (but specified) "filename" be overwritten by the obsolete
"name", if available.

REVIEW: 116973
Update copyright year for Yuri
Add a note that these indexes MUST NOT be changed

Thanks to paalsteek about hitting this in his work for the \Flagged column. I
should have coded this (see MainWindow::applySizesAndState) in an extensible
way.
Tasks: indicate activity via KeepMailboxOpenTask while it's fetching the UIDs and flags of new arrivals

This fixes that inconsistency while a GUI might fail to show any indication
while the network was stuck and we were waiting for the UIDs to arrive.

REVIEW: 116989
Merge remote-tracking branch 'upstream/master'