First batch of new docstrings.
Merge branch 'dev' into features/doc-string-audit
Doc strings for config.go and decoders.go.
Add docstrings for filters.go.
Removed (obsolete) TimeoutError definition.
Tweak to a filter doc string, added doc strings to inputs.go.
Remove unused LogfileInput attribute.
Doc strings for LogfileInput.
Tweak for correctness in inputs.go, add docstrings to outputs.go.
Add pipeline_runner.go doc strings.
Doc strings for router.go.
Merge branch 'dev' into features/doc-string-audit

Conflicts:
	pipeline/logfile_input.go
Merge branch 'features/doc-string-audit' into dev