Layout problems in rooms when rotating

[thombles]

Testing Riot 0.4.0 on iPad Mini 4 running iOS 10.3.2.

These steps reproduce four problems which I'll bundle together:

• When you make a room full screen, the back button does not appear until you perform a rotate
• When you make a room full screen from portrait, messages are missing/truncated until you perform a rotate
• When you go "back" from a full screen room, both the back and full screen buttons are displayed simultaneously in the tool bar, until you either rotate or reopen the room.
• When you go "back" from full screen, you are not fully scrolled to the bottom any more.

Start off with a room in portrait mode:

Go full screen. Note the missing back button, and the fact that everything's truncated to the left part of the screen and some messages are missing:

Rotate to landscape to make the messages display correctly, plus the back button:

Back to portrait, all fine:

Now press the back button, and I get both buttons at once in the toolbar and I am scrolled back some distance whereas I was previously at the bottom: