ManualInstruction should abort the transformation if it fails for any reason

[fabiocarvalho777]

Currently, If the MD file does not exist, the ManualInstruction TU results in ERROR, but does not abort the transformation.

However, that by itself is a major error, because the end user won't have a chance to complete that manual instruction.

Having said that, Butterfly must abort the transformation whenever ManualIsntruction fails by default (for whatever reason).

That should be documented properly in ManualInstruction javadoc, and the developer should still have a chance to change this behavior by calling abortOnFailure(false).

In addition to that, it must fail fast in the case of an inexistent MD file (check it during definition time, as opposed to transformation time).

Acceptance Criteria

1. ManualInstruction by default must abort the transformation if it fails for whatever reason
2. Developer must have a chance to change this behavior by calling abortOnFailure(false)
3. In the case of an inexistent MD file, it must fail fast (check it during definition time, as opposed to transformation time)
4. Make sure all of this is documented completely and clearly in the contract (javadoc)