Make zip builds more portable (python & ffmpeg)

[joeyballentine]

This PR does three things:

• Moves the forge config out of package.json and into its own config file
• Uses a build hook to write a portable file to the zip, if the build is a zip
• Checks for the existence of this file when checking for python/ffmpeg, and if the file exists will use the current executable directory rather than appdata.

Note: Settings still save to appdata. I will accomplish that next.

[RunDevelopment]

The empty portable file seems like a hack to me, but it's fine for now, I guess.

[joeyballentine]

The empty portable file seems like a hack to me, but it's fine for now, I guess.

That's quite literally the only way i can possibly think of to do it

[RunDevelopment]

I would probably make it a setting we don't show in the UI, but I honestly think that we should rethink how we store settings anyway. The whole "I'm shadowing built-in localStorage" doesn't smell like a best practice to me either.

So let's keep the portable file for now and think about settings as a totality later.

[RunDevelopment]

One comment. GTG otherwise. Feel free to merge after resolving the comment.