drop_buffer
Description:
Drop the buffer currently queued in this.
Parameters:
| this | the pad where to drop any pending buffer | 
Returns:
| TRUE if there was a buffer queued in this, or FALSE if not. | 
Drop the buffer currently queued in this.
| this | the pad where to drop any pending buffer | 
| TRUE if there was a buffer queued in this, or FALSE if not. |