Creating duplicate connections using the Backend class allows the
connections and their handling to be tested at the same time that the old
system is in place. This should make it somewhat easier to grasp what
changes and where when the new implementation is taken into use.
The session commands are now duplicated as SessionCommand objects This
allows for an easier migration from the old session command implementation
to the new one.
The temporary table detection and handling now uses C++ containers to
store the set of temporary tables. The detection also uses the new query
classifier field info API to detect which tables and databases are
targeted.
Cleaned up the readwritesplit main header. The structs were named to their
typedef names so that no code changes are required. The structs should be
renamed if/when they are converted to proper C++ classes.
