Read boards from Espruino, cleanup boards, better pin location

main.css
- new style for selected parameter in code editor
espruino_board.js
- use style to mark selected parameter instead of selection, easier
editing
- select of pins for parameter now by right mouse click, to avoid
problems with other plugins in codemirror
- cleanup to select pins, new function getMatchingPins
datafiles for pins
- better location handling to match position in board image