Code improvements


DN2URI.java:
Do not decode DN when only the list of URIs is needed:
- extracted methods decodeUrisOnly(), decode0(), decodeDN(), decodeUris()
- used Map.Entry instead of Pair because it maps exactly to the role of DN2URI index (where DN is the key and List of URIs is the value).


EntryContainer.java:
Extracted method getNumberOfEntriesInBaseDN0() to avoid creating a sub transaction (used by RootContainer).

VerifyJob.java:
Used SuffixContainer constants.