Rewrite tuncateTable() using Operators
Rmove getTableStatistics() from DMLFunctions
Remove (now unused) write, update and delete from DMLFunctions
Use new scan helper in PostgresServerFilesITBase
Remove cursor, scan, and row collector methods
Remove most of the (now unused) classes in com.foundationdb.server.api.dml.scan
Remove unnecessary ClientAPIBase and DXLMiddleMan
Remove (no unused) IndexCursorUnidirectionalLexicographic
Remove GrowableByteBuffer and ByteBufferFactory
Remove deprecated/unused TableStatistics
Remove empty updateAISGeneration method
merge nathanlws: Remove most of DMLFunctions

Merge pull request #1509 from nathanlws/sql-layer/remove-dml-functions
https://github.com/FoundationDB/sql-layer/pull/1509