Linux compatability

Soooo............... I didn't have another Mac computer lying around, so I decided to hack on this to run on Linux.

:sparkles: :sparkles: :sparkles: :sparkles: TADA :sparkles: :sparkles: :sparkles: :sparkles: 

This PR modifies the bootstrap code to get things running on Ubuntu Linux. As with all things, there are caveats.

## Install Requirements
The following packages need to be installed. The current pattern in OSX is to get pre-reqs via `brew`, but that didn't seem right. I'd love feedback on the best course of action here.

* `build-essential`
* `python`
* `python-virtualenv`
* `avrdude`
* `scons`
* `libcurl-dev`
* `ruby1.9.1`
* `rubygems`

## Caveats

* Cameras - I currently have a hack going with `motion`, but that's *sorta* out of scope. Input here also accepted
* `s3g` - The current version of `s3g` does not support Rev 2 of the Replicator 2 (diff USB VID), and newer versions have problemo building.