Lint checks should not test these, they are historical documents,
and we don't want to encourage silly changes to them to satisfy
a checker.
Hopefully makes travis pass again on master.
Tree-SHA512: 37e6716c4fd5e8a4e579f9b84042e6b0ac224836b6c851cd1ca3f7d46611ffd3003bed0ae08dd0457f69d6eaa485a0d21c631e7ef16b14bdb0f2f78ea700332d
This adds a new CHECK_DOC check that looks for newly introduced trailing
whitespace. Existing trailing whitespace (of which there is plenty!)
will not trigger an error.
This is written in a generic way so that new lint-*.sh scripts can be
added to contrib/devtools/, as I'd like to contribute additional lint
checks in the future.