(build) Fix classpath usage when running xtend compiler
(build) Remove useless reference to org.jgrapht plugin
(build) Fix Xtend classpath for tests plugin
(build) Update script to also build tests feature
(tests) Add a new basic script, for unit tests execution
(tests) Improve paths in tests run script
(refactoring) Rename script to execute tests
(tests) Add documentation for test script
(tests) Oops, fix unwanted variable redefinition