Don't obscure corner of picture with timestamp

[bkil]

It looks out of place and it can result in obscure bugs such as #1101 that is made worse by the text wrapping. I don't personally like rounded corners of image uploads either, but that can be less of a bother.

Why can't the timestamp be just placed outside the image?

It could be rendered to the right of it just as it is placed after textual messages.