libjq-go v1.6.1

• use jq-1.6 with updates to b6be13d5 commit from master:
  • faster jq_compile than from jq-1.6 tag
  • the sequence of jq_compile calls works after errors in fromjson/tonumber
  • see #10
• fixes for build script and submodules
  • thank you @cdevienne and @distorhead