Adds tests quant parsing; Adds unbounded ranges

[cirocosta]

#2

---

commit 1f94258d9b3691b057595b6030f869911147b194

  Previously it wasn't possible to make use of unbounded ranges in the
  CLI: --range 1 would be equivalent to --range 1,0.
  After this comming, such ranges are possible: --range 1 is equivalente
  to --range 1,math.MathFloat64.

  The commit also adds tests for the parsing method given that it's not
  trivial.

commit fe04829d7724a0734c8fcd2ae97442a460b2e536  
  Applies negative value constraint to range parse