Minor: refactoring
Fixed #2266. Management of serializers for SBTree
Minor: remove unnecessary operations from SBTreeBonsai.create()
Fixed #2266. Management of serializers for SBTree
Minor: refactoring
Merge branch 'develop' into orientdb-2266

Conflicts:
	core/src/main/java/com/orientechnologies/orient/core/index/OIndexMultiValues.java
	core/src/main/java/com/orientechnologies/orient/core/index/OIndexOneValue.java
	core/src/main/java/com/orientechnologies/orient/core/index/engine/OSBTreeIndexEngine.java
	core/src/main/java/com/orientechnologies/orient/core/index/sbtree/local/OSBTree.java