Added graph:
new file:   IC_74HC595_Graph/74hc595-chart/graph-74HC595.dot
new file:   IC_74HC595_Graph/74hc595-chart/graph.png

minor changes:
modified:   IC_74HC595_Graph/IC_74HC595_Graph.fzz
modified:   tiltswitch/tiltswitch.ino
readme for graph