Adding SH1107 support

[ricardomatias]

I've forked the code for the SSD1306 over at github.com/niklauslee/ssd1306 and I'm trying to adapt it to a SH1107 driver. I've added the initialization commands, but whilst they are being sent I get a "Device Write Error".
The code used is in example/ex_i2c_128x64.js. Perhaps someone could take a look at it and see why this might be the case. I've based my changes on this code from Adafruit.