units.clean: Cleans units from units.val to remove the suffix (.o2, .flow, etc)
Description
These are the 'clean' or parsed names we want to use in outputs. All input
units get parsed to these.
Usage
# S3 method for clean
units(unit, is)
Details
Could make code much simpler with a regex for everything after the "." but i
like the specificity of this.