Code simplifications


Importer.java:
Renamed putInIdContainerMap() to putInIndexIDToIndexMap().
Fixed Tree parameter names.
RebuildIndexManager:
- changed dn2id and dn2uri fields to reBuildDn2id and rebuildDn2uri boolean fields.
- in setIndexesListsToBeRebuilt(), rebuildIndexMap(), clearIndexesToBeRebuilt() simplified the code\ + extracted mustRebuild() method
- in clearIndexesToBeRebuilt(), fixed a bug: it should reference the computed vlvIndexes rather than entryContainer.getVLVIndexes()
- inlined fillIndexMap() and setTrusted()