Refactored importer to make it easier to configure and understand
Moved base classes in a more appropriate package (theses classes are used by both the importer and the exporter)
Bug fix in enumeration importation / exportation.
The string based approach was not precise enough since enumeration values are not the same between the two models
Merge remote-tracking branch 'origin/master'

Conflicts:
	workspace/org.openetcs.es3f/bin/org/openetcs/es3f/ImportUtil.class
	workspace/org.openetcs.es3f/src/org/openetcs/es3f/ImportUtil.java
Bug fix in enumeration importation / exportation.
The string based approach was not precise enough since enumeration values are not the same between the two models