Improve error message when module is not found in runner
Initialize ceylon.build.runner test module
#32 tests for goal annotation discovery
Remove unused imports and spaces
#32 tests for include annotation discovery
#32 test for goal annotation retrieval
#32 test goal name taken from annotation / function
#32 tests for tasks invocation on toplevel functions / objects

Tests for tasks invocation
following signatures are supported:
- `Anything()`
- `Outcome(Context)`
- `Task()`
- `{Task*}()`