Write Python script for mvn internal libs

* For unintrusive setup we should first start by making
use of the internal libraries in src/lib.
* internal_libs.json contains data of all internal libs
* add_maven_dependencies.py parses the JSON and adds jars
  to local maven repository
* add_maven_dependencies.py prints out what to add to your pom.xml
Ignore PipeTestFile.xml
Implement very basic maven build system

* Restructure project to maven preferred structure
  i.e.
  -src
    -main
      -java
      -resources
    -test
      -java
      -resources
* Point maven at local libaries which were installed with
  python script
* Change hardcoded simpleNet.xml file to point to new location in
  PNMLTransformerTest.java
Replace local jars with those that can be found on on mvnrepository
Make phase to execute main of Pipe.java

* Add exec plugin to pom.xml
  Run with mvn exec:java
Update README.md

Explain mvn installation
Update README.md

Explain local lib installation
Merge pull request #3 from sarahtattersall/maven-simple

Maven simple