API Revamp: Removed methods hasX and removeX from the role slots with multiplicity of one.
Refactored Framework internal code to comply with the latest generated API.
Removed methods 'getXCount', 'hasAnyX', 'hasX', 'getXSet' and 'getXIterator' from the role slots with multiplicity of *.
Modified the code generated for consistency checks to use the new generated API.
Renamed generated method 'getXpto' to 'getXptoSet'
Refactor: Changed invocations to 'getXpto' to comply with the new generated API.
Updated Tests to use the new Generated API.
Change the role names in DML files to be in singular form
Merge pull request #1 from smmf/review/feature/generated-revamp

Change the role names in DML files to be in singular form
Merge pull request #103 from jcarvalho/feature/generated-revamp

Revamp the API generated from the Domain Model