update .AUTHORS

@karl-wette I've noticed that several contributors from our group don't show up in the package-level author lists on the docs pages, which seem to come directly from the .AUTHORS files, and indeed those are all 6 years old by now. I figured out that those files seem to be controlled from lalsuite/gnuscripts/lalsuite_library_top.am, but I couldn't get any of those make targets to do anything locally. Could you have a go, and/or give some instructions?

(Also there's a note here still pointing to Redmine.)