improved Importer, Variable, and StudyInfo

loading ALL studies except 083, 085:
- defaults set in roda.properties
- added a new CSV file for placing studies in catalogs (except those 2
studies)

changed CSV for catalog to allow putting ALL studies inside catalogs or
root

Variable has natural sorting by ID (implements Comparable + equals,
hashCode)

list of variables returned by "/studyinfo/{id}" is now sorted in the
same order as DDI / CSV

improved speed of "/studyinfo/{id}"

DDI Importer catches all exceptions and informs _which_ study import
failed (if any)

!!! everybody should update the "roda-ddi" SVN project (renamed 083, 085
studies) !!!