Trimming white space left of values in parsing?

[acesnik]

See discussion here #33

[rfellers]

My vote is to "aggressively trim" the whitespace when parsing. This means to trim from both sides of the descriptor and from both sides of the colon (if present).

This has the downside of losing whitespace information when potentially writing the ProForma back out, but I think this is a small price to pay for simple rule of "we remove all extra whitespace"