Atlas 04/24/2021

Various bug fixes.

Add command #JMP(-1) to allow automatically jumping to the end of the file.

I've included additions from g8tzetal's versions for file insertion and also putting in warnings when going past a spot (#WARN($POS, "COMMENT_HERE")) when inserting (#INSERT("FILENAME", "ID")).

I'm naming this based on the date I'm uploading but I've been using this for years. I've just been lazy about getting it uploaded to github :)