more bug fixes.


ndb/src/kernel/blocks/dbdict/Dbdict.cpp:
  DropIndex -
  1) return Invalid version 
  2) Mark as IS_DROPPING so that 2 simulatainious threads can't drop it
ndb/src/ndbapi/NdbDictionary.cpp:
  Changed listIndex from taking table name to taking table id
  (should be index version aswell)
ndb/src/ndbapi/NdbDictionaryImpl.cpp:
  List indexes using id
  Fix log towards m_globalHash
ndb/src/ndbapi/NdbDictionaryImpl.hpp:
  List indexes using tableid (indexid)