Add new export formats

*Specify export format as request param 'format'
*Formats are 'mwDeprecated','mediawiki', and 'zotero'
*Default if no format specified is mwDeprecated
*Default if format invalid is zotero
*mediawiki format intended for use with TemplateData

Change-Id: I2683604289e965a32f1dc06a58cb1e9b9ca60b39