Add references from doi/10.1371/journal.pcbi.1005283.s004 data

[mwatts15]

The data added in #284 includes some references, but the document that's being cited can't be found unless you go to the source. The a data linked in #284 includes full citations. Luckily, most of these have PMIDs so we don't have to work to hard to pull out a key for the Evidence object.

These three don't have PMIDs in the supplementary references:

1	Sze JY, Victor M, Loer C, Shi Y, Ruvkun G. Food and metabolic signaling defects in a Caenorhabditis elegans serotonin-synthesis mutant. Nature. 2000;403:560-4.�
12	Shyn SI. Cameleon Reveals a Physiologic Correlate for Alternative Behavorial States in C. Elegans Egg-Laying: University of California, San Diego; 2003.
58	Geary T, Kubiak T, Larsen M, Lowery D, inventorsG protein-coupled receptor like receptors and modulators thereof2002.

and the first two are used in the data set we've added to PyOpenWorm.

Relates to: #284