small update on the LJ test
Merge branch 'feature/leftjoin' of github.com:ontop/ontop into feature/leftjoin
fix an issue when null in is the head of a rule
test case for multiple maps for one property
some change in the test
Merge branch 'feature/leftjoin' of https://github.com/ontop/ontop.git into feature/leftjoin
some change
Conflicts:
	quest-test/src/test/java/it/unibz/krdb/obda/unfold/LeftJoinTestVirtual.java
changed the bug in the push type
test case 3 for differnt templates
small changes to unfolder
changes in pushtypes -> for example with URI with multiple variables
temp fix the arity problem in the SQLGenerator
small change to unfolding push types
change the unfolder to integrate and use multiple predicate definition
list obtained from the meta mappinge expander
result: stop unfolding in case of a predicate having multiple rule
defintions
fix column type -1 and test expected result
Merge branch 'feature/leftjoin' into feature/aggregates2

Conflicts:
	reformulation-core/src/main/java/it/unibz/krdb/obda/owlrefplatform/core/sql/SQLGenerator.java
Aggregates shitty test case