Adjust Notice's order
Update navigation drawer to follow Material Design

* Add raw avatar placeholder.
* Add background for drawer's top.
* Tweak `ic_avatar_placeholder.png`.
Change color palette for light theme

* Move the single view's style into `style.xml`
Fix the NumberFormatException if we haven't set uid during showing user avatar
Rename some fields and colors
Simplify `ReplyFragment` UI
Change Chinese strings order and fix typos