Decouple {EE|GDB}Helper from JUnit so that it gets easier to use the new test style

o Introduced new top-level test classes: {EE|GDB}JUnitSuite, EEJUnitSuite
o Converted EqualsTest to use EEFunSuite as an example
Rename new suite classes to Cypher{JUnit|Fun}Suite and move to commons

o Adds a provided dependency from cypher to commons for tests
Rename StatisticsChecker to QueryStatisticsTestSupport

o Clean up of QueryStatisticsTestSupport and synced with QueryStatistics again
o Change QS.deleted{Node|Rel} => QS.{node|rel}Deleted for consistency
Merge pull request #1980 from boggle/2.0-funtest

Better support for using new Cypher test style with {EE|GDB}Helper
Merge pull request #1959 from cleishm/ast-plan-cache

Use Cypher query cache to find plans based on AST
Add rewriter to solve arithmetic expressions using literals
Add rewriter for naming pattern elements
Add rewriter for normalizing match predicates