I've been looking for the solution, but it seems, that nobody made it yet (or it's really deep burried somewhere).
I'll try to explain it as simple as possible:
when I insert image into post using the standard editor i get:
<img src="mypath/image.jpg" alt="My Image" title="My Image" width="1024" height="576" class="alignnone size-large wp-image-1234" />
...and I'd love to get rid of this part: class="alignnone size-large wp-image-1234"
Could someone help me to make a plugin, or edit some files in a way to stop this being included with every picture inserted? ...or else I'll be forced to remove it every time by hand ;) ...
Thanks in advance,