This addresses #3016 by checking whether any of the media items in an event have altered exposure times (as opposed to the alteration type "metadata, time" which is valid for whole events, but not individual images or videos).  If one or more media items has an exposure time change, the entire event is marked as 'dirty' so the sidebar will know to re-examine the fields and refresh them.
This addresses #3016 by checking whether any of the media items in an event have altered exposure times (as opposed to the alteration type "metadata, time" which is valid for whole events, but not individual images or videos).  If one or more media items has an exposure time change, the entire event is marked as 'dirty' so the sidebar will know to re-examine the fields and refresh them.

In addition, if the event doesn't yet have user-assigned name, a "metadata, name" alteration is sent up, since the name displayed for the event will need to change from 'Event XXXX' to the start date of the event.


h4ck3rm1k3/shotwell,abrauchli/shotwell,jof/shotwell,polymeris/shotwell,abrauchli/shotwell,Sanva/shotwell-gsoc,damianmoore/shotwell,h4ck3rm1k3/shotwell,jof/shotwell,polymeris/shotwell,jof/shotwell,ritchiewilson/shotwell,Sanva/shotwell-gsoc,ritchiewilson/shotwell,Sanva/shotwell-gsoc,ritchiewilson/shotwell,damianmoore/shotwell,h4ck3rm1k3/shotwell,jimbonator/shotwell,abrauchli/shotwell,polymeris/shotwell,jimbonator/shotwell,jimbonator/shotwell,damianmoore/shotwell