Handle bad embed

On medium.com if we type a bad embed data, it's converted in a normal paragraph.
So I've handle it the same way.

If we fail to retrieve content for an embed, instead of showing an ugly message to the user,
we just convert the content into a normal paragraph
Merge pull request #115 from j0k3r/handle-bad-embed

Handle bad embed
add acceptFileTypes option to image fileupload
Remove image toolbar when removing a photo

It avoids image toolbar to stay open when we remove a photo
Merge pull request #118 from j0k3r/patch-1

Remove image toolbar when removing a photo