This adds the numSubordinates and hasSubordinates operational attribute support in OpenDS.
   - Implemented as virtual attributes
   - They are enabled by default
   - numSubordinates and hasSubordinates methods added to the backend API and implemented for all existing backends
   - JE implementation uses the id2children index to keep count of the number of subordinates for each entry.
   - The behavior of exceeding the index-entry-limit (ALL-IDs) has changed to store a 8 byte entry ID set count with the most significant bit 
set to 1 instead of a 0 byte array to signify the index-entry-limit has been exceeded. The previous format is still compatible but all requests 
for numSubordinates will return undefined (-1).
   - The DBTest tool is also included in this fix. This can be used to list root containers, entry containers, database containers, index 
status, as well as dumping a database with or without decoding the data. 

Fix for issues 43 and 72