Revert "Merge remote-tracking branch 'origin/2.0-maint'"

This reverts commit 065898a0e7549bbc090cd0313ed68ee75b7d64d1, reversing
changes made to 99aca6ba44417b1ce6df252dc1809f496d7cc630.
Typo in testdb path for example.
Refactor Expand + OptionalExpand to use QueryPlan
Refactor Projection (along with Skip, Limit, Sort, SortedLimit)  to use QueryPlan
Refactor Join  to use QueryPlan
Refactor CartesianProduct  to use QueryPlan
Refactor Optional  to use QueryPlan
Refactor remaining Apply variants and OuterHashJoin to use QueryPlan
Add Visitor support for Query{Plan, Graph} and removed coveredIds from LogicalPlanStringVisitor
Remove coveredIds from LogicalPlan
Remove solved from LogicalPlan
Merge pull request #2370 from boggle/externalized-qg

Externalized qg
Merge branch 'master' into 2.1-updatepuller-behave

Conflicts:
	enterprise/ha/src/main/java/org/neo4j/kernel/ha/com/master/MasterImpl.java
	enterprise/ha/src/test/java/org/neo4j/ha/TestSlaveOnlyCluster.java
	enterprise/ha/src/test/java/org/neo4j/ha/TransactionConstraintsIT.java