Ensure LOAD CSV returns Collections of Strings
Add the toInt function
Add the toFloat function
Mention toInt in the LOAD CSV tutorial
Use CypherException for unexpected types in toInt, toFloat

For other kinds of errors, such as invalid strings, a standard IllegalArgumentException
will be thrown and Cypher will wrap it around in a CypherException as a cause.
Improve type checking
Add toStr() alias for str()
Return null for parse failures in toFloat/toInt
Make sure csv-file directory isn't created prematurely
Update CHANGES.txt
Folding and rewriting of ASTs
Replace fixed rewriteTopDown/BottomUp methods with Rewriter objects
Merge pull request #1921 from cleishm/ast-rewriting

Add rewriting to Cypher AST
Add support for parsing autocommit clause
Add autocommit information to AbstractQuery by introducing new AutocommitQuery

o Introduce PipeInfo in ExecutionPlanBuilder to track this info as a replacement for PipeAndIsUpdating
Evaluate expression to compute autocommit batch size

o Refactored QueryState to be able to instantiate it without collecting statistics
Reject negative autocommit batch size and use default size for null expressions
Move semantic checking of autocommit to the AST
Move AUTOCOMMIT to the beginning of a Query
Move semantic check of autocommit to AST from ExecutionPlanBuilder