Changed ToolingModelBuilder to use Project instead of ProjectInternal.
Some minor tidy-ups for the tooling API sample apps.
Added a sample for exposing a custom tooling model.
Minor doc updates:
- Remove deprecated Compile task from DSL doc tasks list
- Fix doc for UpToDateRule
Added integration test for supporting ivy dependency excludes
Updates to incremental build spec
Use a more recent snapshot.
Updated the build-initialisation spec to flesh out the next few stories, to make the thing usable.
Added some notes to spec.
Moved the 'code coverage' story from the reporting to the testing-improvements spec and added some initial notes.
Tweak to the spec.
Updated spec.
A few more updates.
Initial port of gradle-jacoco into core.
Added config options for Jacoco test tasks.

The test tasks used for default Jacoco configuration, including
the report tasks and Sonar execution data.
Only execute JacocoReport if there is any execution data.
Add jacoco as a plugin project.
Fix Jacoco Sonar config when root project doesn't apply Jacoco plugin.

When the Jacoco plugin was applied to a subproject and the Sonar or
Sonar Runner plugin to the root project, the Jacoco reports weren't
configured on the Sonar projects.
Added Jacoco multiversion integration test. Doesn't work yet.
enable multiple versions in the JacocoPluginVersionIntegrationTest