gh-409 Thor PIPE to support ,OPT
gh-409 Thor PIPE to support ,OPT

Add support for ,OPT on PipeWrite activity in Thor. PipeRead/Pipethrough and hthor/roxie
were already added in prior commits

Fixes gh-409.

Signed-off-by: Richard Chapman <5900d56196fe29dba8e3ae556d57eae28e9f0195@hpccsystems.com>

afishbeck/HPCC-Platform,afishbeck/HPCC-Platform,afishbeck/HPCC-Platform,afishbeck/HPCC-Platform,afishbeck/HPCC-Platform,afishbeck/HPCC-Platform