Automate builds with Eclipse Tycho

While Eclipse Tycho is unbelievably awful, it's still better than nothing. Apparently a good percentage (50%+) of Eclipse plug-ins are using it for their builds.

To invoke:

* All plug-ins may be built using `mvn compile`.
* All tests may be run using `mvn integration-test.`

Currently, there are failing tests and they are ignored so that Maven will continue to run the remaining tests. A number of these failures are probably due to the test harness. Once the test failures are fixed, we ignoring test failures can be disabled. After that, continuous integration with Travis CI (or something else) should be a snap to set up.

Other alterations:

* Added a root `.project` file so root files like the parent pom were easier to edit in Eclipse.
* Added `target/` to root `.gitignore` since Maven uses `target/` subdirectories for builds.

As an added bonus, easymock is now automatically obtained from Eclipse Orbit. This should mean that  easymock can be removed from the repository.

Update: Apache Commons Lang is also on Orbit, as is json.org (no idea how the hell that got through the Eclipse Foundation's legal department; then again, Mr. Crockford did give IBM alone a special grant to use the code for evil according to Wikipedia). It also has GSON, a JSON serialization library without an asinine non-FOSS license.