writing the size of the statement cache size. This parameter can make a huge
difference with the length of time taken to prepare statements. Added support
for setting the statement tag when preparing a statement. Both of these were
requested by Bjorn Sandberg who also provided an initial patch. Cleaned up some
error context strings as well.
when a new statement is prepared since it is very likely that the new statement
will not be compatible with the old and having to clear it manually each time
would be rather tedious.
