[prefix-sharing] Fixed some anomalies that lead to trees having uneven height.
[prefix-sharing] Refactored BTree code for readability.
[prefix-sharing] Precomputed node size.
Merge remote-tracking branch 'origin/prefix-sharing' into prefix-sharing

Conflicts:
	src/org/zoodb/internal/server/index/btree/BTree.java
[prefix-sharing] Added additional size recomputations after redistributions.
[prefix-sharing] Added missing size recomputations.
[prefix-sharing] Prefix now kept as a field on the BTree node.
[prefix-sharing] Added class for simple profiling.
[prefix-sharing] Changed divisions with shift variants.
[prefix-sharing] Re-wrote insert to avoid creating a temporary node.
Merge remote-tracking branch 'origin/prefix-sharing' into prefix-sharing