I think that if we're going to do a massive line-ending-change (my vote is to not to), it would be best to do it using something like filter-branch that rewrites history so we don't have a commit that touches every line in the project.
This is an extremely good point. I will take some time to figure out if it is possible to make these changes while preserving the git history.
if I can do it, it will mean careful coordination with contributors, as it will necessitate a force push to github.
Finally, regarding maintenance: wouldn't any pull requests with the wrong line endings show a "dirty" diff? if so, it would be a simple matter for the maintainer merging the code to have the contributor rework their pull request with the appropriate line endings.
further, as mentioned in the linked bug, I can include a .gitattributes with the pr which should take care of ensuring all contributors are using the correct git settings