fetch now tracks launch commands and continues if a ruleset does not contain a launch...

fetch now tracks launch commands and continues if a ruleset does not contain a launch command. This allows rule files to set vars to be used by rules that follow. Additionally, this commit has a first pass at bidirectional shell comm with tracking of output lcoation, input range, and selection. It's buggy still, but it's a start towards an editable terminal like 9term