calling stopped callback in error case

calling stopped callback in error case

[Title] call stopped callback in all error case in event thread
[Issue#] N/A
[Problem] sometimes one thread does not get event anymore. lockup.
[Cause] client can't know error case when broken socket with download-provider
[Solution] alert error by callback in all error case
[SCMRequest] N/A

fix the crash in clear_socket
 - gallery call url_download_destory in callback function.
fix lockup issue by read block
 - if failed to send the packet in url_download_stop,
   add exception handling to not call ipc_read if failed ipc_send()

Change-Id: I534f6d5c41868fdc77f795c445fe79677541fcec