Add rebuildRegionIndex function implementation. RegionIndex will rebuild
the index based on the deserialized index type and arguments.
Upon start, it can read from FS. also add log when loading from FS.
Another thing needs to fix: region split problem and loading daughter
regions from file system.
Make split for both implementation. Add split method to
abstractPluggable class. Customer needs to implements their own split
method if they want to have their own index implementation
fix the bug in removeValueFromIdx in HybridIndex
Add rwLocks to HybridIndex
Merge pull request #1 from kestefanie/master

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