libav: fixed compiling issues with more recent versions of libavcodec
Only compare the serieslink field when comparing an event with a serieslink auto recording.  Previously tvh was also comparing other fields, including title, which broke some serieslink recordings (e.g. if the episodes had unique titles).  Fix by adamsutton.
Description tag fix
Merge pull request #281 from petriposio/issue/1689

Description tag fix
- Fix possible memory leak - hc->hc_reply queue may hold malloc'd memory after return of http_server_requests
- Fix memory leak - free cwc->cwc_cryptoworks_emm.shared_emm before set to NULL, if not NULL it must be malloc'd on line 1839 (case 0x84)
- Fix memory leak -  cwc->cwc_id and cwc->cwc_viaccess_emm.shared_emm may are not free'd on cleanup
- Fix memory leak - free tda->tda_fe_info in dvb_adapter_destroy
- Fix memory leak - dtf in tda->tda_table_feed queue, malloc'd in dvb_adapter.c - line 1115 was not free'd
- Fix memory leak -  in case htmsg_binary_des0 return's something < 0, n and f was not free'd
- Fix memory leak -  cfg is was free'd allocated in dvr_config_create - line 1218
- Fix memory leaks -  Some fields in tda was not free'd. tda_rootpath, tda_fe_path, tda_demux_path and tda_dvr_path
- Fix memory leak -  In case that img is already in cache, img->url was not free'd
- Fix memory leak - After cwc_running is set to 0 in capmt_destroy, capmt and capmt->id was not free'd
- Fix memory leak - st->es_section allocated in tsdemux.c - line 108, was not free'd
- Fix - instead of make a fixed malloc(50), just do a char addrstr[50]
- Fix -  buf is assigned to to cm->cm_data with is defined 'uint8_t cm_data[CWS_NETMSGSIZE];' part of the cwc_message_t, never malloc'd and should be free'd
- Fix - exchange char* portBuf = malloc(6) to char* port_buf[6] - no need for malloc here
- Fix - exchange a fixed malloc(50) to char addrstr[50] - no need for malloc here
- Fix - In case that num parameter was NULL, epg_episode_num_deserialize funcion would return newly calloc'd
  epg_episode_num_t, but it's never used like this, so better remove the calloc, and make it void return.