Fix citation ranges

[Klortho]

Example article:

• PMC1762412
• http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1762412/
• http://dx.doi.org/10.1371/journal.pone.0000133
• ftp://ftp.ncbi.nlm.nih.gov/pub/pmc/aa/e1/PLoS_ONE_2006_Dec_27_1(1)_e133.tar.gz

Problem:

Note that the number of citations is different: wikisource has 39; PMC has 44.

Probably, these are due to citation ranges in the body of the text. For example, see the in-text citation range in PMC, in the introduction, is "[2]-[4]". In Wikisource, this is translated as "[2]-[3]", because it only recognizes that there are two articles being cited.

[Wrote this up in JATS4R: https://github.com/JATS4R/JATS4R-Participant-Hub/issues/20]

My understanding is that there is a huge amount of variation in the way these are tagged in PMC.