[WIP] AppBar DOM-like structure

[quanglam2807]

This PR will make AppBar worked like Toolbar

<AppBar zDepth={1} noGutter={true}>
  <AppBarGroup key={0} style={{ float: 'left' }}>
    <IconButton onTouchTap={this._onLeftIconButtonTouchTap}>
       <FontIcon className="mui-icon-menu" />
    </IconButton>
    <AppBarTitle text={title}/>
  </AppBarGroup>
  <AppBarGroup key={1} style={{ float: 'right' }}>
    {githubButton}
  </AppBarGroup>
</AppBar>

Also, this will fix other related components: Toolbar, FontButton, FontIcon,...
Still WIP but please give reviews and comments.

[freeslugs]

ooh +1 this would be a great feature.
can you post a pic of this in action? 😄

[tleunen]

An update on this @quanglam2807 ? :)

[quanglam2807]

@freeslugs Sorry for late response. Everything looks the same as the current app bar. 💃
@tleunen I'm quite busy these days. Anyway, I'm rebasing the PR right now. Just a few edits for CSS and documentations and it's ready to go. 👯

[quanglam2807]

Moving to new branch