[master][refactor] remove unused header
[master][refactor] change send_http_post(fd) to send_http_post(cvr_setting)
[master][refactor] change global variable 'cvr' to local variable
[master][refactor] remove global variable 'prog_arg'
[master][refactor] rename struct 'struct cvr_setting' to 'CVR'
[master][refactor] refactor function 'run'

1. change function 'void *run(void *data)' to 'int run(CVR *cvr)'
2. show error log when select < 0
3. include errno.h
4. define BUF_LEN
[master][refactor] rename function 'config_checking' to 'crv_check_config'
[master][refactor] remove unused fields in CVR, and refactor function 'run'
[master][refactor] refactor function 'connect_ipcam' and 'connect_server'
[master][refactor] refactor function 'send_http_post'