remodeled salt-graph model instead of using EObject as Label.value, now
a EDataType is used, and the methods convertObjectToString and
createStringFromObject are used for serialization and deserialization.

A lot of tests does not work, since they use old SaltXML files.
removed field valueString from model element Label. All tests are
running.
don't know
updated eclipse project settings
Just removed some blank lines