Merge branch 'es/chainlint-output'

Teach chainlint.pl to annotate the original test definition instead
of the token stream.

* es/chainlint-output:
  chainlint: annotate original test definition rather than token stream
  chainlint: latch start/end position of each token
  chainlint: tighten accuracy when consuming input stream
  chainlint: add explanatory comments