Legacy version of the bluetrack app

Hello Jon!

first of all, congrats for the app! very useful. I was looking for a bluetooth tracking app over the android market and I found yours. It works well but I have to set up a testbed with some old devices (nexus one) with android 2.3.6. As bluetrack only supports android 3.0+, I have modified your app to support android from API 10 (2.3.3).

It requires the android support library (v4) and the actionbarsherlock library. It has been tested on several devices and it is working properly.

I have made this pull request in case you want to add a new branch in your project for this legacy version. It is not intended to be merged in the master brach, but in a new one (legacy or whatever) for the further development and support of this legacy version. I can't make a pull request to a non existing branch, so I have made it to the the master one.

Cheers!