Bringing a Stardew Valley Content Patcher mod up to date

I needed a distraction recently so I worked on an unofficial update to someone else's Content Patcher mod. I'm not including the entire mod here because I don't have permission (I just edited their code to match 1.6 for my own game). It might be useful for someone else who needs to alter a similar mod.

(Technically the 1.5 version should work? There was just one minor change that I made in the actual code by deleting 2 characters.)
( technical stuff about Stardew Valley Modding )