#L search

[emmaccode]

I have mentioned before how I would like to find markdown headings, #97, Well I would also like to be able to find lines, like Github by providing #L. For example.
https://github.com/#L50.

This will almost certainly make #55 a lot easier :)

[emmaccode]

I think we are going to skip this -- each evaluation is a Meta evaluation from within a containerized sub-module -- it makes more sense, for output sake, to have cell numbers be based specifically on that cell.