imgcache.js in process milestone

CORS enabled:
1. install chrome extension: access-control-allow-origin
2. apache config Header add Access-Control-Allow-Origin * :
http://blog.csdn.net/linxiangyao/article/details/6107617

conflict in collection-repeat with directive img-cache,
collection-repeat只渲染当前窗口中的item, 导致窗口以外的img-cache不起作用, 同时,
下拉增加的item中的img-cache指令(directive)也不起作用.

https://app.yinxiang.com/shard/s9/nl/3688389/e34a5b16-fe71-4c23-bc4a-fdf380277f92/?csrfBusterToken=U%3D3847c5%3AP%3D%2F%3AE%3D149f300fcdd%3AS%3D26c5474d1a24543992d5ba2ba68420b3

http://forum.ionicframework.com/t/v1-0-0-beta-11-collection-repeat-doesnt-work-with-directives/8267/11

http://codepen.io/waynecheah/pen/wfeEo/?editors=101