Update quantities.js

- updated pica and point length units to contemporary desktop publishing standard
- current units are Traditional American standard
- the contemporary standard is more likely to be the desired unit
- http://en.wikipedia.org/wiki/Point_(typography)
- 1 point = 0.000352777778 meters
- http://en.wikipedia.org/wiki/Pica_(typography)
- 1 pica = 0.00423333333 meters