UX improvements

[micahflee]

Fixes #56.

This PR does this:

• On account pages, it removes the Cyd account bar at the bottom
• On account pages, the menu button in the top-right now has Cyd account-related buttons in it
• The home tab shows all sections on the same screen without scrolling, and the Cyd avatar is much smaller
• The nav bar at the bottom uses consistent icons with the home tab