Improve button wrapping behavior

[WesCossick]

By wrapping the two "from" line buttons on the composition popup in a <span class="pull-right"> tag, they will now break lines together instead of separately. See below:

Before

After

[ervee]

Hi Wes, great UI work I see from you. Thanks for chipping in.

On my screen (Sony Xperia Z5 compact, it looks like this.

There is so little room for showing the body of the email. Is that something that could be improved also?

[ervee]

Ps, this is before your patch, which might improve it a little so I'll have to test that out.

[WesCossick]

@ervee I definitely agree that the composition area for the message body can become too tiny. I'm looking into the best way of resolving that now. I think the root of the issue is that the dynamic min-height attribute has no enforced minimum, so it can be given a minimum height that is far too small to be useful.

However, this PR fixes a different bug that isn't really related.