Improve layout and readability of contact details page.

[hodgestar]

Currently the contact details page seems really oddly and un-compactly laid out to me. Currently it looks like:

...

Perhaps we need to allow the non-editable information (extras and subcriptions) to re-flow to a second column?

[hodgestar]

@justinvdm @SteveBarnett Thoughts when you're back?

[SteveBarnett]

@hodgestar Agreed. I'll have a quick look today.

[hodgestar]

Woot. Tx.

[SteveBarnett]

We should:

• remove col-md-4 from the div;
• add a col-md-4 class to section.profile;
• add a col-md-4 class and col-md-push-1 class to section.extras;
• move the Save changes button to outside the div (so that it doesn't wrap funny).

@hodgestar writing this ^^^ rather than doing this because I should be doing numi stuff and I don't want to get told off by @badlard. Also worried about running into my usual getting-my-local-vumi-go-running rabbit hole. :D

[hodgestar]

Not ready for review, but I started by cleaning up the structure to look more like idiomatic bootstrap and less special sauce.