Updating dnlib to latest

[JasonRancourt]

I'm a long time developer but a bit new to github. We've been using ConfuserEx for a while from it's previous branch, but recently found this fork, and it's much appreciated, especially the MSBuild integration!

I'd like to propose updating the dnlib dependency to the latest version (4.4), which has support for .winmd assemblies. I've got a clone of the master branch from mkaring/ConfuserEx with the change (only one other file required to change besides the package reference), and would like to make a pull request, but I wasn't sure if I should do so by making a fork of this repository, or if I can create a remote branch in this repo and do the pull request from there.

Sorry for the noobie question.