Merge pull request #42 from Vido/master

pcDuino Review merge
Update README.rst
changed exit to ImportError when PyMata absent
changing exit to ImportError in pingo.rpi when RPi.GPIO is not installed
Create NOTES.rst
Merge pull request #43 from Vido/master

Review on pcDuino V1 and V3
merge and add new slides
Vdd -> Vcc fix
Vdd is wrong!
implemented StrKeyDict for board.pins; simplified GhostBoard
bumped version to 0.2.0
added example double blink
Merge branch 'master' of https://github.com/garoa/pingo
added example double blink
script to map 7 segment display
Merge branch 'master' of https://github.com/garoa/pingo
script for dojo with Arduino XXL panel
minor fixes do pt-br slides
moved resources files to garoa/pingo-resources repository
added __iter__ to StrKeyDict to fix bug that made a loop 'for p in board.pins:' return pins and not keys, and raise a KeyError on pin 20 on an Arduino with pins 0-20 and A0-A5
added first part: Led, with threaded blink method