Make it a little clearer that using a custom logger disables the default output.
Change the signature of Test.filter(Closure) to be more consistent with the established configuration method pattern.
Support starting JavaExec and Test task processes in debug mode by the --debugJvm invocation time switch.

We can't use `--debug` because it's already taken for enabling debug logging.
Switch to use unqualified 'classifier' attribute in IvyArtifactName

Ivy Artifact instances seem to use both qualified and unqualified attributes
  (eg. ModuleDescriptor created from DependencyDescriptor has artifacts with unqualified 'classifier' attribute)
So now we just treat qualified and unqualified attributes on Artifact as equivalent.
Merge branch 'release' into 'master'