cleaner & more correct implementation of where_sql, fixes bug combining PK ranges and only: conditions.  add spec coverage.
reduce the max insert size, have seem some poor performance from mysql
write out regex, not actually implemented by the libstdc++ version that came with ubuntu 12.04
for mysql, set sql_mode to traditional,pipes_as_compat so we hear about errors and so anonymizers are cross-compatible to postgresql (and ansi standard sql in general)