ceylon.test: add support for Test Anything Protocol

Adds
* a second `TestListener` that prints the test results in [Test Anything Protocol v13](http://testanything.org/tap-version-13-specification.html) format
* a `--tap` option to the runner to use a `TapLoggingListener` instead of a `SimpleLoggingListener`.

Benefits: can be used with the [TAP Jenkins plugin](https://wiki.jenkins-ci.org/display/JENKINS/TAP+Plugin) until someone writes a proper Jenkins - ceylon.test binding. Can also be used with [various other TAP consumers](http://testanything.org/consumers.html) (although some of them might not support version 13).

TAP looks like this:
```yaml
TAP version 13
ok 1 - test.my.module::testFeature
  ---
  elapsed: 163
  ...
not ok 2 - test.my.module::testOtherFeature
  ---
  elapsed: 11
  severity: failure
  actual: |
    Lorem ipsum dolor sit amet ,
    consetetur sadipscing elitr ,
    sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat ,
    sed diam voluptua .
  expected: |
    Lorem ipsum dolor sit amet,
    consetetur sadipscing elitr,
    sed diam nonumy eirmod tempor invidunt ut labore et dolore magna aliquyam erat,
    sed diam voluptua.
  ...
not ok 3 - test.my.module::testProposedFeature # SKIP ignored
  ---
  reason: not yet implemented
  ...
not ok 4 - test.my.module::testBrokenFeature 
  ---
  elapsed: 15
  severity: error
  exception: |
    java.lang.Exception: Error
        at test.my.module.testBrokenFeature_.testBrokenFeature(testBrokenFeature.ceylon:3)
        at com.redhat.ceylon.compiler.java.runtime.metamodel.AppliedFunction.$call$(AppliedFunction.java:257)
        at com.redhat.ceylon.compiler.java.Util.apply(Util.java:934)
        at com.redhat.ceylon.compiler.java.runtime.metamodel.Metamodel.apply(Metamodel.java:1099)
        at com.redhat.ceylon.compiler.java.runtime.metamodel.AppliedFunction.apply(AppliedFunction.java:413)
        at com.redhat.ceylon.compiler.java.runtime.metamodel.FreeFunction.invoke(FreeFunction.java:262)
        at com.redhat.ceylon.compiler.java.runtime.metamodel.FreeFunction.invoke(FreeFunction.java:251)
        <-- snip -->
        (not snipped in actual output, only for pull request)
  ...
1..4