Fixed some syslog levels.
Added error UAVSRV_ERR_FAILOPENBACK: failure openning backup file.
Fixed uavsrv_err set to REQINIT in uavsrv_connect().
Fixed seg fault if no videos given: check for videos str len and not null in uavsrv_start().
Moved syslog messages out of uavsrv_restore and uavsrv_save functions.
Added check for recent timestamp in handler_aileron and handler_throttle: UDP does not garanties order of arrival, therefore check timestamp to avoid executing recent command and then old command.
Added socket openning + binding in uavsrv_recover instead of calling uavsrv_connect() outside.