This is a replacement for the dubious approach when the
extension itself was used to run benchmarks to detect
performance and filtering behavior regressions.
The main nodejs flavor is "npm", which is to be used to
lint/test and the publication of an official npm
package -- and by design it has dependencies on mocha,
eslint, etc.
A new flavor "dig" has been created with minimal
dependencies and which purpose is to easily allow to
write specialized code to investigate local code changes
in uBO -- and it's not meant for publication.
Consequently, "make nodejs" has been replaced with
"make npm", and a new "dig" target has been added to the
makefile, to be used for instrumenting local code changes
for investigation purpose.
