Scaled image doesn't align to center

[karmatosed]

To reproduce:

• New post
• Insert new image
• Scale an image
• No alignment shows
• Left align: it pops over
• Center and this shows:

[hedgefield]

The problem is mainly that it looks like you have left-center-right controls, but those actually affect the block itself, with the options float left - wide - float right (so it can appear next to a text block).

I can imagine that having the block take up the full width of the content column but have the image within it aligned to the right would be nice, so maybe there should be two sets of alignment controls? I don't know, that might get confusing, maybe for v1 it's best to only offer options to align the image within the block. If we ever do column layouts the block alignment problem will solve itself.

[mtias]

Closing as duplicate of #2548.