clean up install/lookup of regexes.{yaml,json}

Reworked the python install command to copy regexes.yaml down into the python package directory, and convert it to json.  Crucically, we do that *before* letting the standard install run, so we can simply specify both files as package_data.  And *that* allows the usual pkg_resources.resource_filename method to work on all platforms (tested on fedora, osx, ubuntu before sending the PR).