It is now used for consoleProject, run, and test. This loader verifies
that all classes loaded through it came from a particular classpath or
from the "root" loader. Root loader here is the launcher loader so that
those classes with native bindings come from that shared loader.
While this increases the verbosity level of `Fork.run()`, it remains
consistent with `Run.run()`. Switching between `fork := false` and
`fork := true` shouldn't change verbosity of log output.
- interrupts task execution only
- no further tasks scheduled
- existing tasks interrupted
- a task must terminate any other started threads when interrupted
- set cancelable to true to enable
- currently, 'run' properly terminates if the application properly
terminates when interrupted
- 'console' does not, 'test' depends on the test framework
- also bundled: set connectInput to true to connect standard input to forked run