* move existing docs to sphinx / autodoc
* add more api documentation
* improve wording on some exception strings
Change-Id: Ia41e14d643d452d92fc8d3c2fb9c4ac9021402e9
"data" is an awfully generic term. Anything stored on a card is data.
This specific code deals with resolving key/pin material from an
external source.
Change-Id: I4c8e1be3e766f7c0565c07b39d48abf8adc375af