Protect RemoteLRS from exceptions in sendRequest
Protect RemoteLRS from exceptions in sendRequest

* This will cause exceptions from fopen and the one we cause for invalid
  status codes to not cause fatal error but instead return an LRS
  response with 'success' set to false and with a message in 'content',
  and in the fopen case allow detection that the request never actually
  made it to the LRS as 'response' itself will be empty
* Add error handling for fopen to provide a more meaningful message when
  PHP is setup without track_errors being on (IOW capture the E_WARNING
  that is generated)

brianjmiller/TinCanPHP,RusticiSoftware/TinCanPHP,garemoko/TinCanPHP