fixes #556 Skip the hot index when doing a first pass of indexes for
uniqueness and multikey checks.
refs #557 Normal callers to NamespaceDetails::serialize will not include
the hot index. Only the hot indexer itself will pass includeHotIndex =
true so that the serialized form will include the hot index. If the hot
index commits, then the new serialized from will commit to the nsindex.
Merge branch 'bugfixes/tokumx-1.2'