v1.47 - Gaussian processes and housekeeping

- added data(Crofoot)
- data(islands) renamed data(Kline)
- various man page updates
- cleaning up namespace (in progress)
- resample accepts optional data list now
- Gaussian process L2 norm added to map2stan as GPL2 distribution.
Still needs a man page, but example added to README
- map2stan coerces index variables to integer now
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