Cleaned up channel initialization in XYZalgorithm and calls to get_required_channels() in algorithm.py

Added channel options to can_produce_data and get_stream_gaps so get_required_channels can be used for XYZAlgorithm functionality

This is done to ensure that the original trace is not changed.

Adren Rigdon authored 7 years ago and Jeremy M Fee committed 7 years ago

Add optional --output-observatory argument to controller to support average algorithm.

Changed update_count to be an optional parameter that defaults to zero for the run_as_update method.

Added an update-limit for the max number of recursions.  Mainly for goes,  but really should work for any algorithm, where the user doesn't care to crawl back days, weeks or years.