removed core project to make a new architecture
added new core project (written in groovy) and base classes such as
DataUnit, AtomicDataUnit, CompositeDataUnit and FunctionDataUnit. also
added tests for these classes
adapted dsl project to use interfaces of the core project and removed
classes that aren't suitable anymore in the new architecture
moved xml files from the sender project to the core project
removed some utility classes as they became obsolete due to the use of
Groovy
moved the remaining utility class (BitOperator) to the core project
added DataUnitFactory classes
adapted the CompositeDataUnit to now support encoding with child
DataUnits whose sizeInBits isn't a multiple of 8. This means that the
data can get concatenated inside single bytes