Add Splunk external search command script for Vast queries
Add Splunk external search command script for Vast queries

- Setup and usage instructions included in help.
- Help output and error messages available in both cmdline and Splunk.
- Uses InterSplunk format to support sending multivalue fields to Splunk.
- Splunk results as events (|vast) or stats (|vaststats).
- Does not use Splunk InterSplunk lib to avoid mv related bug.
- Option to use line-by-line stream mode (-s)
  (for single source results with single header - Multivalues are not split in this mode).
  Stream mode discards all headers and respective values diferent than the first one received.
- Non stream mode (default) supports mutiple sources and multivalues.
- Option to output _raw field (-r) (some Splunk commands process the _raw field).
- Option to override the timestamp field. (-t)
- Option to select query node (-n)
- Option to limit results (-e)

pmos69/vast,pmos69/vast,vast-io/vast,vast-io/vast,mavam/vast,vast-io/vast,mavam/vast,pmos69/vast,mavam/vast,pmos69/vast,vast-io/vast,mavam/vast,vast-io/vast