Creating rosjava package structure and importing hokuyo module

This PR creates the catkin and gradle wrapper for the repository and imports the hokuyo module in it.

I tested it to build and deploy to maven local when executing:
- Gradle from command line
- catkin_make
- imported and built from Android Studio

Note this will also require:
- Updating android_core once more to update the dependencies for the anrdoid hokuyo tutorial
- (optional+recommended) add this repo to the .rosinstall file for rosjava