add_extension_onebyte_header
Description:
Adds a RFC 5285 header extension with a one byte header to the end of the RTP header.
If there is already a RFC 5285 header extension with a one byte header, the new extension will be appended. It will not work if there is already a header extension that does not follow the mechanism described in RFC 5285 or if there is a header extension with a two bytes header as described in RFC 5285. In that case, use add_extension_twobytes_header
Parameters:
| this | the RTP packet | 
| id | The ID of the header extension (between 1 and 14). | 
| data | location for data | 
| size | the size of the data in bytes | 
Returns:
| true if header extension could be added |