fixing test issue - validation request is not propagated to children tasks since we don't keep references to them
Fix javadoc
introducing test utilities
adding more tests
Fix up tests, make canCommit() more correct
Fix install-time dependent adding; add tests
Add TCCL support to tasks
State machine diagram
Adjust state machine for better transaction encapsulation
fixing builder design pattern + adding dependencies null check
All transaction methods prepare(), commit() & rollback() can be called only once
additional test scenarios - ommiting transaction.prepare method call
adding empty transaction tests
introducing utility methods for test setup & tearDown
eliminating good-for-nothing PREPARE_UNDOING transaction state
refactoring abstract test class to util package
first transition test and failing
renaming transition NEW_to_CANCELLED -> NEW_to_TERMINATED
Fixing TaskControllerImpl cancellation issue:
 * removing FLAG_CANCEL_REQ check from execCancelled() - the flag is never set when Executable.cancelled() is called
enhancing transitions test case