LED Strip (sorry the branch name is still neopixel_strip)

Here is the pull request for the generic version from [here](https://github.com/firmata/arduino/issues/167)
Try moving NeopixelFirmata.cpp and NeopixelFirmata.h to /utility/devices/ and compiling under both the latest version of Arduino 1.5.x and 1.0.x. Arduino keeps changing the way they compile files within subdirectories you may run into an issue here. I would prefer to keep device-specific code under a /devices/ subdirectory if possible.