bibtex fails to parse certain complex data strings from Greycite, switch to JSON

[cboettig]

E.g. cannot parse bibtex data returned by greycite API for this address: http://link.springer.com/chapter/10.1007/978-1-4684-4106-2_14

This would be avoided and the whole thing would be cleaner if we parsed JSON data returned by Greycite instead.