Added initial pom file for boostrap project

In response to appium/appium#353, I've added an initial version of a pom.xml file that can be used to build the bootstrap project.  The pom file relies on the [Maven Android SDK Deployer](https://github.com/mosabua/maven-android-sdk-deployer) project, which will deploy the Android SDK jars to a local Maven repository.  

To install the Android 4.2 dependencies within your local Maven repository, run `mvn -P4.2 install` from the maven-android-sdk-deployer directory.

Let me know what you think:)