grab_epg
========
eg:
gem grab_epg

proxy_list=Grabepg.get_topfast_list
Grabepg.getchannels.each do |channel,url|
  Grabepg.getschedule(channel,url,proxy_list)
end


Grabepg.getschedule 的返回：
channel_schedule 是日期的时间表
show_schedule 是根据节目的时间表
 {"channel_schedule"=>channel_schedule,"show_schedule"=>@show_schedule}


grab epg