Combine adding 'shared' files with 'min' files in `_js_dist`

[TillerBurr]

This fixes #142

To reduce code duplication, the -shared in webpack.config.js was changed to .shared. Then this can be combined with the extension of the _js_dist using the min version.

Since it is hard to tell if there is a shared file until it is generated, a shared_resources list was created that defaults to ["min"]. If a shared file is generated, then 'shared' would need to be appended to this list. Without checking to see if a file exists, this is simplest fix I could think of.