define new process states, documentation

Signed-off-by: Christian Lüthold <biocodr@gmail.com>
rename cancel() -> rollback()

Signed-off-by: Christian Lüthold <biocodr@gmail.com>
rename start() -> execute()

Signed-off-by: Christian Lüthold <biocodr@gmail.com>
make API symmetric

Signed-off-by: Christian Lüthold <biocodr@gmail.com>
adapted ProcessState transition tests

Signed-off-by: Christian Lüthold <biocodr@gmail.com>
changed IProcessComponentListener

Signed-off-by: Christian Lüthold <biocodr@gmail.com>
updated ProcessStep docu

Signed-off-by: Christian Lüthold <biocodr@gmail.com>
implement listener notifications

Signed-off-by: Christian Lüthold <biocodr@gmail.com>
IProcessComponentListener tests

Signed-off-by: Christian Lüthold <biocodr@gmail.com>