$tflags should be defaulted to 0 to avoid warnings about uninitialized value $tflags in bitwise #38
Description
As tflags are documented as optional in the costructor of LMDB::Txn ($Txn = LMDB::Txn->new ( $Env [, $tflags ] )) the $tflags constructor argument should be defaulted to 0 to avoid the tedious warning about uninitialized value in bitwise.