Add endpoint timeout to originate command

I noticed that default 10 seconds timeout may not be enough in some cases which that caused originate api command timeout and duplicated UUID errors (it tries to send originate cmd again while call already exists). Also, with endpoint_timeout you can configure for how long we should wait for fax tone/answer on called fax machine.
Merge pull request #564 from remac/patch-2

Add endpoint timeout to originate command