fixes for avr-gcc 4.7

PROGMEM and prog_ changes to be compatible with a newer gcc compiler

Signed-off-by: Christopher Hall <christopherhall.hsw@gmail.com>
[Sketches] add demo for Wyolum AlaMode

Simple slide show from binary image files stored on a micro SD card

Signed-off-by: Christopher Hall <christopherhall.hsw@gmail.com>