Added toStringItemSeparator to PmAttrListCfg
PmAttrBase: Fixed getValueType() for more complex generics definitions

  e.g. for list attributes.
  added also a PmAttrList test
Added test for @PmAttrListCfg.toStringItemSeparator
Changes after review
Merge pull request #5 from pm4j/PmAttrListCfg_toStringItemSeparator

Pm attr list cfg to string item separator