put all Eclipse settings under version control
made it possbile to wait for jobs

- this makes it possible to wait for them via JobManager.join(...)
- implemented/overwrote belongsTo(Object family) for all our jobs
- default implementation returns false - see Job.belongsTo(...)
added tests

- the 'plugin' project has to export its packages to make them
  accessible in the 'tests' project
- tests are currently buildable with Eclipse 3.5 & 3.6 due to the
  restriction to Groovy 1.7
- these files have to be in sync concerning the Groovy version:
  - MANIFEST.MF (org.codehaus.groovy;bundle-version="[1.7.0,1.7.99)")
  - org.eclipse.jdt.groovy.core.prefs (groovy.compiler.level=17)
- added some files from the Groovy Eclipse plugin tests
  - ide-test/org.codehaus.groovy.eclipse.tests
  - they could also be required since plugin version 2.9.x
  - this is only supported in Eclipse 3.7 which would raise the dependency
using Tycho to test the plugin with Maven

- using the groovy-eclipse-compiler to compile Groovy classes with Maven
- using Tycho 0.18.1 in combination with groovy-eclipse-compiler 2.7.0-01
  as there have been problems with newer versions
- using Eclipse 3.6 "Helios" for testing (currently used for development)
  - the Eclipse version can be changed via the repository url
  - the Groovy-Eclipse version has to be changed accordingly
- explicitly setting the groovy-eclipse-batch version to 1.7.x
  - this makes sure that everything is compiled with Groovy 1.7
    (same as in Eclipse itself)
  - otherwise the groovy-eclipse-compiler plugin can use
    groovy-eclipse-batch 1.8.x
  - this can result in NoClassDefFoundError for ValueRecorder as its
    package changed from Groovy 1.7 to 1.8
- explicitly disabling the ui harness (even if it's disabled by default)
added Travis integration
created README containing Travis build status