• 重构BottomBarLayout，xml中不需要指定item的布局，通过设置数据源导入tab;
• 支持中间图标凸起、中间图标宽高设置、距离底部高度等

English:

• Refactored BottomBarLayout, no need to specify item layout in xml, import tab by setting data source;
• Support middle icon bulge, middle icon width and height setting, height from bottom