Make Stalker stalk itself

Add basic stalker config for Java to stalker
Set version to 0.4.0
Update stalker dependency
Configure multi-project setup for tests/ subproject

- Add buildscript script plugin

- Reuse buildscript script plugin with all subprojects under
  tests/
Update copyright
Update README.md

Add Travis build status image
Merge pull request #28 from jle/make_stalker_use_stalker

Make stalker use stalker
Set stalker extension defaults for android projects.

Stalker extension defaults are set for android projects that use android plugin
0.9.+. This version was chosen because the DSL for Library Projects is the
same as for application projects. Supporting older android plugin versions
would require a little more complexity.

* Update sample android projects to use android plugin 0.9.0 and remove stalker
configuration.
* Add tests.
Update .travis.yml

Configure Travis CI to install necessary Android SDK dependencies
Configure only a single environment build
Inline exports in .travis.yml
Fix PATH in .travis.yml
Remove gradlew installation

- gradlew is already included in the repo
Merge pull request #26 from VandalSoftware/set-defaults

Set stalker extension defaults for android projects.