name refactors in SQL parser
continue refactor in the Mapping2DatalogConverter class
continue name refactor in Mapping2DatalogConverter
Merge branch 'develop' into feature/name-refactor

Conflicts:
	obdalib-core/src/main/java/it/unibz/krdb/obda/parser/TableNameVisitor.java
	obdalib-core/src/main/java/it/unibz/krdb/obda/parser/WhereClauseVisitor.java
	obdalib-core/src/main/java/it/unibz/krdb/obda/utils/Mapping2DatalogConverter.java
continue name refactor
first version of visitor pattern in Mapping2DatalogConverter
fix the stackoverflow problem with regex_like
finish the visitor pattern implementation of Mapping2Datalog Converter
further cleaning
formatting
Merge branch 'feature/name-refactor' into develop